<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:e6ed6eb3-46a2-403c-a2ec-87e797e1403f,g:7a5914ae-3dda-4c49-b732-b534e2b57093-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.marriott.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="mar-20251231.xsd#CONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_f66b9e2c-61a6-4ba3-aaf9-ad8533ac61c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_StatementTable_f66b9e2c-61a6-4ba3-aaf9-ad8533ac61c7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_e924c545-6938-44f8-b051-0a225d1d2d2b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_f66b9e2c-61a6-4ba3-aaf9-ad8533ac61c7" xlink:to="loc_srt_ProductOrServiceAxis_e924c545-6938-44f8-b051-0a225d1d2d2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_e924c545-6938-44f8-b051-0a225d1d2d2b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_e924c545-6938-44f8-b051-0a225d1d2d2b" xlink:to="loc_srt_ProductsAndServicesDomain_e924c545-6938-44f8-b051-0a225d1d2d2b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_f1dd59df-f1e3-46f9-87c1-74df81209397" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_e924c545-6938-44f8-b051-0a225d1d2d2b" xlink:to="loc_srt_ProductsAndServicesDomain_f1dd59df-f1e3-46f9-87c1-74df81209397" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_FeeServiceMember_ce5af428-7e26-412b-8d2d-074132d10973" xlink:href="mar-20251231.xsd#mar_FeeServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_f1dd59df-f1e3-46f9-87c1-74df81209397" xlink:to="loc_mar_FeeServiceMember_ce5af428-7e26-412b-8d2d-074132d10973" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FranchiseMember_f2610230-80ef-4911-952d-baae563a5ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FranchiseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_FeeServiceMember_ce5af428-7e26-412b-8d2d-074132d10973" xlink:to="loc_us-gaap_FranchiseMember_f2610230-80ef-4911-952d-baae563a5ce8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementServiceBaseMember_cf14dfe6-12ae-4628-8742-ad18698d46c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementServiceBaseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_FeeServiceMember_ce5af428-7e26-412b-8d2d-074132d10973" xlink:to="loc_us-gaap_ManagementServiceBaseMember_cf14dfe6-12ae-4628-8742-ad18698d46c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementServiceIncentiveMember_78710d62-68b2-4e2b-abd4-563c0ca488e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementServiceIncentiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_FeeServiceMember_ce5af428-7e26-412b-8d2d-074132d10973" xlink:to="loc_us-gaap_ManagementServiceIncentiveMember_78710d62-68b2-4e2b-abd4-563c0ca488e7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_OwnedLeasedandOtherMember_a5c58c59-3496-482e-971d-1d49f26f8a51" xlink:href="mar-20251231.xsd#mar_OwnedLeasedandOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_f1dd59df-f1e3-46f9-87c1-74df81209397" xlink:to="loc_mar_OwnedLeasedandOtherMember_a5c58c59-3496-482e-971d-1d49f26f8a51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ReimbursementsMember_62d520a9-d134-40fe-914b-38804e8e3e76" xlink:href="mar-20251231.xsd#mar_ReimbursementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_f1dd59df-f1e3-46f9-87c1-74df81209397" xlink:to="loc_mar_ReimbursementsMember_62d520a9-d134-40fe-914b-38804e8e3e76" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_0bc269f7-b1cf-4b52-b067-c2acb25817da" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_RevenuesAbstract_0bc269f7-b1cf-4b52-b067-c2acb25817da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_RevenuesGrossOfCapitalizedContractCostAmortization_e6a3804e-09a7-462c-8ee8-bc0e4678b839" xlink:href="mar-20251231.xsd#mar_RevenuesGrossOfCapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0bc269f7-b1cf-4b52-b067-c2acb25817da" xlink:to="loc_mar_RevenuesGrossOfCapitalizedContractCostAmortization_e6a3804e-09a7-462c-8ee8-bc0e4678b839" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAmortization_180026c4-98a6-41c7-9902-9647b2455ec2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0bc269f7-b1cf-4b52-b067-c2acb25817da" xlink:to="loc_us-gaap_CapitalizedContractCostAmortization_180026c4-98a6-41c7-9902-9647b2455ec2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_44558dd3-d373-4292-8cbe-c72aec13ee09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0bc269f7-b1cf-4b52-b067-c2acb25817da" xlink:to="loc_us-gaap_Revenues_44558dd3-d373-4292-8cbe-c72aec13ee09" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpensesAbstract_db80ae91-67bd-48d1-abdc-859dee4522de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_CostsAndExpensesAbstract_db80ae91-67bd-48d1-abdc-859dee4522de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_714f2241-f0a5-4de0-870a-9365f3c293fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_db80ae91-67bd-48d1-abdc-859dee4522de" xlink:to="loc_us-gaap_CostOfRevenue_714f2241-f0a5-4de0-870a-9365f3c293fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_DepreciationAmortizationAndOtherExcludingCapitalizedContractCostAmortization_299a0bb3-ab03-4152-94c6-251e5a2de91b" xlink:href="mar-20251231.xsd#mar_DepreciationAmortizationAndOtherExcludingCapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_db80ae91-67bd-48d1-abdc-859dee4522de" xlink:to="loc_mar_DepreciationAmortizationAndOtherExcludingCapitalizedContractCostAmortization_299a0bb3-ab03-4152-94c6-251e5a2de91b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_da7762ed-6316-45c6-a029-812ed480bccc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_db80ae91-67bd-48d1-abdc-859dee4522de" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_da7762ed-6316-45c6-a029-812ed480bccc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_RestructuringAndMergerRelatedChargesRecoveriesAndOther_ed35d5c7-7840-409b-8a29-c1eca7162dcd" xlink:href="mar-20251231.xsd#mar_RestructuringAndMergerRelatedChargesRecoveriesAndOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_db80ae91-67bd-48d1-abdc-859dee4522de" xlink:to="loc_mar_RestructuringAndMergerRelatedChargesRecoveriesAndOther_ed35d5c7-7840-409b-8a29-c1eca7162dcd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_b3331b22-af19-4501-a4b3-32b47989f6f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_db80ae91-67bd-48d1-abdc-859dee4522de" xlink:to="loc_us-gaap_CostsAndExpenses_b3331b22-af19-4501-a4b3-32b47989f6f3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_c7e136ec-e247-429a-b524-b93aaae017d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_OperatingIncomeLoss_c7e136ec-e247-429a-b524-b93aaae017d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_90807df7-05d0-48cd-98df-6debf71f53f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_90807df7-05d0-48cd-98df-6debf71f53f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_ad31ba04-7756-4077-8b4d-20613801d5ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_InterestExpenseNonoperating_ad31ba04-7756-4077-8b4d-20613801d5ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_4154cab7-d735-49cd-b2f1-cbb736da52a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_InvestmentIncomeInterest_4154cab7-d735-49cd-b2f1-cbb736da52a8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_ee6c894e-fcc6-43c0-9763-f0dc0661a4b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_ee6c894e-fcc6-43c0-9763-f0dc0661a4b5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_d319a881-bc4f-42de-b8c4-39f37fadc9e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_d319a881-bc4f-42de-b8c4-39f37fadc9e8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_e561272e-f378-4ba9-8dc7-130e745b182d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_e561272e-f378-4ba9-8dc7-130e745b182d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_bfb09610-2af4-42de-94da-82975120b704" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_NetIncomeLoss_bfb09610-2af4-42de-94da-82975120b704" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_ab553d1a-6811-48bc-a032-3629e9659e12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ad936d5d-d598-4ba7-9a22-fcd26c561cc4" xlink:to="loc_us-gaap_EarningsPerShareAbstract_ab553d1a-6811-48bc-a032-3629e9659e12" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_6f5ee8c1-548d-40b6-ac77-4af8a5e933a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_ab553d1a-6811-48bc-a032-3629e9659e12" xlink:to="loc_us-gaap_EarningsPerShareBasic_6f5ee8c1-548d-40b6-ac77-4af8a5e933a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_85dbab7c-5ca4-4516-a77c-a497a96efef0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_ab553d1a-6811-48bc-a032-3629e9659e12" xlink:to="loc_us-gaap_EarningsPerShareDiluted_85dbab7c-5ca4-4516-a77c-a497a96efef0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="mar-20251231.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_fa06a9f5-8676-4d99-82bf-f3c1b6e5bd71" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_ee4a3439-7eda-4e80-a1dc-bed61b6ab6a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_fa06a9f5-8676-4d99-82bf-f3c1b6e5bd71" xlink:to="loc_us-gaap_StatementTable_ee4a3439-7eda-4e80-a1dc-bed61b6ab6a5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_5562de84-20cb-4630-a913-ff45bce6e840" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_ee4a3439-7eda-4e80-a1dc-bed61b6ab6a5" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_5562de84-20cb-4630-a913-ff45bce6e840" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_5562de84-20cb-4630-a913-ff45bce6e840_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_5562de84-20cb-4630-a913-ff45bce6e840" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_5562de84-20cb-4630-a913-ff45bce6e840_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea9dfa24-e4bb-4d2a-993a-97e950186ed4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_5562de84-20cb-4630-a913-ff45bce6e840" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea9dfa24-e4bb-4d2a-993a-97e950186ed4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_38cab09e-86d5-4da2-817e-ab9c92e707f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea9dfa24-e4bb-4d2a-993a-97e950186ed4" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_38cab09e-86d5-4da2-817e-ab9c92e707f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ContractAcquisitionCostsAndOtherMember_38f7473f-dcd8-4352-8013-46e43ad4fe4c" xlink:href="mar-20251231.xsd#mar_ContractAcquisitionCostsAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea9dfa24-e4bb-4d2a-993a-97e950186ed4" xlink:to="loc_mar_ContractAcquisitionCostsAndOtherMember_38f7473f-dcd8-4352-8013-46e43ad4fe4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_240587ab-1108-499a-818b-32de822e4278" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_ee4a3439-7eda-4e80-a1dc-bed61b6ab6a5" xlink:to="loc_srt_ProductOrServiceAxis_240587ab-1108-499a-818b-32de822e4278" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_240587ab-1108-499a-818b-32de822e4278_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_240587ab-1108-499a-818b-32de822e4278" xlink:to="loc_srt_ProductsAndServicesDomain_240587ab-1108-499a-818b-32de822e4278_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_a7464e59-75f4-418e-93a7-3832ffe417eb" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_240587ab-1108-499a-818b-32de822e4278" xlink:to="loc_srt_ProductsAndServicesDomain_a7464e59-75f4-418e-93a7-3832ffe417eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LoyaltyProgramMember_7fea9b29-ac48-427d-87fc-672a155e8a4a" xlink:href="mar-20251231.xsd#mar_LoyaltyProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a7464e59-75f4-418e-93a7-3832ffe417eb" xlink:to="loc_mar_LoyaltyProgramMember_7fea9b29-ac48-427d-87fc-672a155e8a4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ContractServicesExcludingLoyaltyProgramMember_291b2313-8d1e-4060-a554-008bbf5e88e2" xlink:href="mar-20251231.xsd#mar_ContractServicesExcludingLoyaltyProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a7464e59-75f4-418e-93a7-3832ffe417eb" xlink:to="loc_mar_ContractServicesExcludingLoyaltyProgramMember_291b2313-8d1e-4060-a554-008bbf5e88e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_fa06a9f5-8676-4d99-82bf-f3c1b6e5bd71" xlink:to="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_d42e3c45-619a-4b4c-b335-4533d9ea56fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_AssetsCurrentAbstract_d42e3c45-619a-4b4c-b335-4533d9ea56fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_77a5de88-02bf-4852-83e9-c23481b210f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_d42e3c45-619a-4b4c-b335-4533d9ea56fe" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_77a5de88-02bf-4852-83e9-c23481b210f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_864a4e3e-8041-4658-9d22-be23e3aee604" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsNotesAndLoansReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_d42e3c45-619a-4b4c-b335-4533d9ea56fe" xlink:to="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_864a4e3e-8041-4658-9d22-be23e3aee604" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssets_b5f963af-a54f-4345-8df6-ce256860f14d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_d42e3c45-619a-4b4c-b335-4533d9ea56fe" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssets_b5f963af-a54f-4345-8df6-ce256860f14d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_07a4711d-e958-4653-9782-ecd5f741a2f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_d42e3c45-619a-4b4c-b335-4533d9ea56fe" xlink:to="loc_us-gaap_AssetsCurrent_07a4711d-e958-4653-9782-ecd5f741a2f1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_5c75d96d-12b9-4b85-82c8-6597fbad09f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_5c75d96d-12b9-4b85-82c8-6597fbad09f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_437a06be-1473-4746-894b-d3e1bfee16ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_437a06be-1473-4746-894b-d3e1bfee16ba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_d5c21b66-7c7a-485c-b699-4162d1bf24c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_437a06be-1473-4746-894b-d3e1bfee16ba" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_d5c21b66-7c7a-485c-b699-4162d1bf24c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_53eaefe7-03a7-45d1-9bc4-7f24d41d50c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_437a06be-1473-4746-894b-d3e1bfee16ba" xlink:to="loc_us-gaap_Goodwill_53eaefe7-03a7-45d1-9bc4-7f24d41d50c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_8c8b2178-c084-4046-86dc-43a0eced0232" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_437a06be-1473-4746-894b-d3e1bfee16ba" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_8c8b2178-c084-4046-86dc-43a0eced0232" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_537baf0e-1c28-46c5-b0b3-ba69d812287f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_EquityMethodInvestments_537baf0e-1c28-46c5-b0b3-ba69d812287f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesAndLoansReceivableNetNoncurrent_8ed83f2b-31f4-4f96-b584-d453adf9eca5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesAndLoansReceivableNetNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_NotesAndLoansReceivableNetNoncurrent_8ed83f2b-31f4-4f96-b584-d453adf9eca5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_489ca901-eadf-4946-88f7-f5106b41f2eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_489ca901-eadf-4946-88f7-f5106b41f2eb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_542f61bf-89ee-4270-8d23-e61a9b3f24f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_542f61bf-89ee-4270-8d23-e61a9b3f24f6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_678383eb-34a1-4fb2-a0a5-030ed697858e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_678383eb-34a1-4fb2-a0a5-030ed697858e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_159855a9-6c96-483d-8ea8-cf70268e940f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_1445320d-54cc-4b68-b269-58cacf77c5bb" xlink:to="loc_us-gaap_Assets_159855a9-6c96-483d-8ea8-cf70268e940f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_fa06a9f5-8676-4d99-82bf-f3c1b6e5bd71" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_f02c37d5-c697-423c-8126-7f87e181a2ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_f02c37d5-c697-423c-8126-7f87e181a2ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableTradeCurrent_7101c70d-e42e-404c-9401-ecba443aba72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableTradeCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:to="loc_us-gaap_AccountsPayableTradeCurrent_7101c70d-e42e-404c-9401-ecba443aba72" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_e21609d2-2110-43f0-aa38-94a1dd4360a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_e21609d2-2110-43f0-aa38-94a1dd4360a6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_22628e88-05b9-46f7-a63a-a62c29b69201" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_22628e88-05b9-46f7-a63a-a62c29b69201" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_8e51f15e-5c5b-4516-8ce0-00b62bfd5ac2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_8e51f15e-5c5b-4516-8ce0-00b62bfd5ac2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_8fe12eb9-ae79-4d95-9cdc-493d85e59155" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_37af573e-f35f-45d3-93e6-9e6341c9e17c" xlink:to="loc_us-gaap_LiabilitiesCurrent_8fe12eb9-ae79-4d95-9cdc-493d85e59155" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_6cdb6717-9173-4335-996b-6201442a491f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_6cdb6717-9173-4335-996b-6201442a491f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_ae4f183e-9044-4883-9cc6-b3a656b0abec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_ae4f183e-9044-4883-9cc6-b3a656b0abec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_5d43ff54-042f-4196-97c0-2a17b850ddd8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_5d43ff54-042f-4196-97c0-2a17b850ddd8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_e61fc4a5-fad2-4cdb-a30e-7cfcac94ee13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_e61fc4a5-fad2-4cdb-a30e-7cfcac94ee13" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_65362cd5-fbdc-4d08-ae0f-4d686c060f07" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_65362cd5-fbdc-4d08-ae0f-4d686c060f07" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_07ba54eb-6be2-46e5-bc3e-80a0c9f1f8a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:to="loc_us-gaap_CommonStockValue_07ba54eb-6be2-46e5-bc3e-80a0c9f1f8a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_be68ba78-5cb8-4618-a7b7-9121ad32aa33" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_be68ba78-5cb8-4618-a7b7-9121ad32aa33" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_81c9fe85-02d6-4ab1-ac93-e747c155e2b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_81c9fe85-02d6-4ab1-ac93-e747c155e2b8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_a2f1bdf3-3db1-47c1-a43a-a771f45ae764" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:to="loc_us-gaap_TreasuryStockCommonValue_a2f1bdf3-3db1-47c1-a43a-a771f45ae764" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_8c1b3381-5f8d-4f32-bb46-f66718a51ad1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_8c1b3381-5f8d-4f32-bb46-f66718a51ad1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_ed020118-91a7-4dd3-8993-136c8d586d1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_48b8e4b8-8ca3-4c92-993e-eb8a6cd79221" xlink:to="loc_us-gaap_StockholdersEquity_ed020118-91a7-4dd3-8993-136c8d586d1c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_10dc7e3a-a0a3-45c6-b482-bb3c44a7dd40" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f94cbb5a-3884-4488-b8ce-efcdbab6828f" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_10dc7e3a-a0a3-45c6-b482-bb3c44a7dd40" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="mar-20251231.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_02d7285c-5fa5-499f-a70c-de04b51caf0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_05e30f36-6710-4b64-a0d8-9d79de617969" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_02d7285c-5fa5-499f-a70c-de04b51caf0d" xlink:to="loc_us-gaap_StatementTable_05e30f36-6710-4b64-a0d8-9d79de617969" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_7454e75a-51b2-4223-978a-471a5d883352" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_05e30f36-6710-4b64-a0d8-9d79de617969" xlink:to="loc_srt_ProductOrServiceAxis_7454e75a-51b2-4223-978a-471a5d883352" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_7454e75a-51b2-4223-978a-471a5d883352_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_7454e75a-51b2-4223-978a-471a5d883352" xlink:to="loc_srt_ProductsAndServicesDomain_7454e75a-51b2-4223-978a-471a5d883352_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_86f96cb7-b612-46fa-8841-8adc7c908db7" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_7454e75a-51b2-4223-978a-471a5d883352" xlink:to="loc_srt_ProductsAndServicesDomain_86f96cb7-b612-46fa-8841-8adc7c908db7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LoyaltyProgramMember_ad971050-9932-47da-bf48-47933d01c76e" xlink:href="mar-20251231.xsd#mar_LoyaltyProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_86f96cb7-b612-46fa-8841-8adc7c908db7" xlink:to="loc_mar_LoyaltyProgramMember_ad971050-9932-47da-bf48-47933d01c76e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_ee02838e-0135-48d6-b5d9-0058a3b8bf77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_02d7285c-5fa5-499f-a70c-de04b51caf0d" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_ee02838e-0135-48d6-b5d9-0058a3b8bf77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_7433df30-5493-4e83-8cda-e4bec8c98f23" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_ee02838e-0135-48d6-b5d9-0058a3b8bf77" xlink:to="loc_us-gaap_NetIncomeLoss_7433df30-5493-4e83-8cda-e4bec8c98f23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_ee02838e-0135-48d6-b5d9-0058a3b8bf77" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_DepreciationAmortizationAndOther_bd6f10f5-f4b5-4088-8722-205bc7a635b1" xlink:href="mar-20251231.xsd#mar_DepreciationAmortizationAndOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_mar_DepreciationAmortizationAndOther_bd6f10f5-f4b5-4088-8722-205bc7a635b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_4b1209ea-b352-4dd7-9865-b65debeebf49" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_us-gaap_ShareBasedCompensation_4b1209ea-b352-4dd7-9865-b65debeebf49" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_NoncashIncomeTaxExpense_5e111a0a-6e6f-4e43-afe8-816ee81c8087" xlink:href="mar-20251231.xsd#mar_NoncashIncomeTaxExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_mar_NoncashIncomeTaxExpense_5e111a0a-6e6f-4e43-afe8-816ee81c8087" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_IncreaseDecreaseInContractWithCustomerLiabilityCash_d0aa3bdb-835d-44eb-8cdc-8f5a4ff78cc8" xlink:href="mar-20251231.xsd#mar_IncreaseDecreaseInContractWithCustomerLiabilityCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_mar_IncreaseDecreaseInContractWithCustomerLiabilityCash_d0aa3bdb-835d-44eb-8cdc-8f5a4ff78cc8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_IncreaseDecreaseInCapitalizedContractCostsNet_162759e6-aeee-4e52-852c-f22683fe21b4" xlink:href="mar-20251231.xsd#mar_IncreaseDecreaseInCapitalizedContractCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_mar_IncreaseDecreaseInCapitalizedContractCostsNet_162759e6-aeee-4e52-852c-f22683fe21b4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_NoncashRestructuringAndMergerRelatedRecoveriesChargesAndOther_6c001365-f84d-432a-b43c-e9cdfdd78bcc" xlink:href="mar-20251231.xsd#mar_NoncashRestructuringAndMergerRelatedRecoveriesChargesAndOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_mar_NoncashRestructuringAndMergerRelatedRecoveriesChargesAndOther_6c001365-f84d-432a-b43c-e9cdfdd78bcc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_IncreaseDecreaseInWorkingCapital_fc46ebfe-33f2-4a16-9d54-759f62e0a89b" xlink:href="mar-20251231.xsd#mar_IncreaseDecreaseInWorkingCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_mar_IncreaseDecreaseInWorkingCapital_fc46ebfe-33f2-4a16-9d54-759f62e0a89b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_ae63cae7-eba6-4c53-9c0d-b79aaba96ead" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_c18119c0-9e05-4e2f-a09e-30d7b8ce2f97" xlink:to="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_ae63cae7-eba6-4c53-9c0d-b79aaba96ead" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_c136a7e6-5478-41c4-9d5b-71adcad8c98f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_ee02838e-0135-48d6-b5d9-0058a3b8bf77" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_c136a7e6-5478-41c4-9d5b-71adcad8c98f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_02d7285c-5fa5-499f-a70c-de04b51caf0d" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_eb52b816-8c0a-411f-9fbe-949567b3e6ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireProductiveAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_eb52b816-8c0a-411f-9fbe-949567b3e6ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_PaymentsForAssetAcquisitions_b60010c1-d6df-4056-8b12-66e11af25bfb" xlink:href="mar-20251231.xsd#mar_PaymentsForAssetAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:to="loc_mar_PaymentsForAssetAcquisitions_b60010c1-d6df-4056-8b12-66e11af25bfb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_800cbcfd-6dc6-4529-b58f-4e32f3dc6f47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_800cbcfd-6dc6-4529-b58f-4e32f3dc6f47" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_PaymentsForLoanAdvances_4c2da75d-6b19-4f05-9ee4-f474eec557bc" xlink:href="mar-20251231.xsd#mar_PaymentsForLoanAdvances"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:to="loc_mar_PaymentsForLoanAdvances_4c2da75d-6b19-4f05-9ee4-f474eec557bc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable_4110409e-acbc-43e3-beb6-2c77c45d9f61" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:to="loc_us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable_4110409e-acbc-43e3-beb6-2c77c45d9f61" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_0eb639f3-8d4b-4aa2-b7fc-01b690b6f3e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_0eb639f3-8d4b-4aa2-b7fc-01b690b6f3e7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_5f7085a0-3e11-4540-8b82-698a4a493d56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_a719005b-e455-41bd-8c6b-6571eb20f61c" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_5f7085a0-3e11-4540-8b82-698a4a493d56" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_02d7285c-5fa5-499f-a70c-de04b51caf0d" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ProceedsFromRepaymentsOfCommercialPaperAndLongTermLinesOfCredit_9fee7ed2-ac7c-4ec2-bd90-aabe27a894cb" xlink:href="mar-20251231.xsd#mar_ProceedsFromRepaymentsOfCommercialPaperAndLongTermLinesOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_mar_ProceedsFromRepaymentsOfCommercialPaperAndLongTermLinesOfCredit_9fee7ed2-ac7c-4ec2-bd90-aabe27a894cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_e1dc8327-1ea9-4937-a8c0-8b228ea70e07" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_e1dc8327-1ea9-4937-a8c0-8b228ea70e07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_8cf20162-8196-4375-8ed2-ffd2fd536324" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_8cf20162-8196-4375-8ed2-ffd2fd536324" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_384b37fd-213c-4d23-a701-3db6010c0101" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_384b37fd-213c-4d23-a701-3db6010c0101" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_3ededbeb-c82f-47f6-9673-23229f056fbf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_3ededbeb-c82f-47f6-9673-23229f056fbf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_b87906df-ba45-4b20-b645-2f5057534cc8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_b87906df-ba45-4b20-b645-2f5057534cc8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_a56262e5-dd1a-49dd-861e-233d4b9da9d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_a56262e5-dd1a-49dd-861e-233d4b9da9d8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_b2c060a2-dd6f-4a8e-a74d-617e6e37ecf0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_b2c060a2-dd6f-4a8e-a74d-617e6e37ecf0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_d47d4d81-1fe6-4223-a4c2-825c26c4e932" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2affd87a-c04b-4950-a64e-f7da61d4a2d2" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_d47d4d81-1fe6-4223-a4c2-825c26c4e932" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_7769a1fe-9879-48d0-910b-910de7f604f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_02d7285c-5fa5-499f-a70c-de04b51caf0d" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_7769a1fe-9879-48d0-910b-910de7f604f8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_14b31fe7-bf7a-48d5-b4eb-54cacf7c5a76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_02d7285c-5fa5-499f-a70c-de04b51caf0d" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_14b31fe7-bf7a-48d5-b4eb-54cacf7c5a76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_fdbb8f46-001c-4394-9255-548c0a5a59ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSDEFICIT" xlink:type="simple" xlink:href="mar-20251231.xsd#CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSDEFICIT"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSDEFICIT" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_986db60b-dbf3-4869-9297-151dda79da51" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_447f70eb-9d81-453d-a0a7-b6a689302d2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_986db60b-dbf3-4869-9297-151dda79da51" xlink:to="loc_us-gaap_StatementTable_447f70eb-9d81-453d-a0a7-b6a689302d2d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_8c75398c-6e91-4d60-924e-ad79f09e75ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_447f70eb-9d81-453d-a0a7-b6a689302d2d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_8c75398c-6e91-4d60-924e-ad79f09e75ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_8c75398c-6e91-4d60-924e-ad79f09e75ea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_8c75398c-6e91-4d60-924e-ad79f09e75ea" xlink:to="loc_us-gaap_EquityComponentDomain_8c75398c-6e91-4d60-924e-ad79f09e75ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_267b6bba-320f-40d7-b17f-7ad96d9bc06a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_8c75398c-6e91-4d60-924e-ad79f09e75ea" xlink:to="loc_us-gaap_EquityComponentDomain_267b6bba-320f-40d7-b17f-7ad96d9bc06a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_8a296d9a-5865-4e1d-a946-70ed6de992ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_267b6bba-320f-40d7-b17f-7ad96d9bc06a" xlink:to="loc_us-gaap_CommonStockMember_8a296d9a-5865-4e1d-a946-70ed6de992ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_df95b7e9-d9b5-4c14-be0e-4f8e61537d56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_267b6bba-320f-40d7-b17f-7ad96d9bc06a" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_df95b7e9-d9b5-4c14-be0e-4f8e61537d56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_0ea39369-ff91-4109-a08f-ffbdc5be06dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_267b6bba-320f-40d7-b17f-7ad96d9bc06a" xlink:to="loc_us-gaap_RetainedEarningsMember_0ea39369-ff91-4109-a08f-ffbdc5be06dc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_9815ecf0-699f-46a9-8279-5a413c43a807" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_267b6bba-320f-40d7-b17f-7ad96d9bc06a" xlink:to="loc_us-gaap_TreasuryStockCommonMember_9815ecf0-699f-46a9-8279-5a413c43a807" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_455c8a0b-75ca-488c-a3aa-e9904914c26d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_267b6bba-320f-40d7-b17f-7ad96d9bc06a" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_455c8a0b-75ca-488c-a3aa-e9904914c26d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_986db60b-dbf3-4869-9297-151dda79da51" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_d77efbb6-0306-48cb-9d22-1f9a199ed2c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_d77efbb6-0306-48cb-9d22-1f9a199ed2c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_32540871-c702-4e55-a659-7e66919a0443" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_StockholdersEquity_32540871-c702-4e55-a659-7e66919a0443" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_a697288b-fd09-49f7-a52f-6ec8a83f2672" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_NetIncomeLoss_a697288b-fd09-49f7-a52f-6ec8a83f2672" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_1073cf4f-164a-425b-828b-7fc0682b5e5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_1073cf4f-164a-425b-828b-7fc0682b5e5b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCash_aabfc4ea-d50e-4c44-a683-f54b2c7506d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_DividendsCash_aabfc4ea-d50e-4c44-a683-f54b2c7506d8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_e3ac8501-6b96-4478-8688-8028f677970c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_e3ac8501-6b96-4478-8688-8028f677970c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_96d8dc68-07c5-4e08-8e23-841d2724f848" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_96d8dc68-07c5-4e08-8e23-841d2724f848" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_e1c8480d-06d1-47b0-839c-c6bdeb78a8ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_e1c8480d-06d1-47b0-839c-c6bdeb78a8ce" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_71ac1ff3-41ce-4654-8ea7-2c10690be4c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e0f4b08d-825d-40c5-ac3a-b8e3f7751842" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_71ac1ff3-41ce-4654-8ea7-2c10690be4c0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_da472ab3-7b9e-4a62-aba4-bd23fe7aedfe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_15f09d19-d413-451b-832d-fa3457f57db6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/BASISOFPRESENTATIONDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#BASISOFPRESENTATIONDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/BASISOFPRESENTATIONDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_c41d3bea-bbf8-4456-8a0d-a33777147866" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_4835b225-33e4-420f-8723-621fab6a15df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_c41d3bea-bbf8-4456-8a0d-a33777147866" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_4835b225-33e4-420f-8723-621fab6a15df" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_7b950e95-4c62-4115-9e02-f21ca13d6d6f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_4835b225-33e4-420f-8723-621fab6a15df" xlink:to="loc_srt_ProductOrServiceAxis_7b950e95-4c62-4115-9e02-f21ca13d6d6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_7b950e95-4c62-4115-9e02-f21ca13d6d6f_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_7b950e95-4c62-4115-9e02-f21ca13d6d6f" xlink:to="loc_srt_ProductsAndServicesDomain_7b950e95-4c62-4115-9e02-f21ca13d6d6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_ea415601-df1e-4379-a9e0-386d4817e6c5" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_7b950e95-4c62-4115-9e02-f21ca13d6d6f" xlink:to="loc_srt_ProductsAndServicesDomain_ea415601-df1e-4379-a9e0-386d4817e6c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_FeeServiceMember_019b023b-4148-7c26-ac6d-71fb17ef9076" xlink:href="mar-20251231.xsd#mar_FeeServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ea415601-df1e-4379-a9e0-386d4817e6c5" xlink:to="loc_mar_FeeServiceMember_019b023b-4148-7c26-ac6d-71fb17ef9076" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CostOfRevenueAmountReclassified_019b023a-355c-78ac-815a-5c724d4377f9" xlink:href="mar-20251231.xsd#mar_CostOfRevenueAmountReclassified"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_c41d3bea-bbf8-4456-8a0d-a33777147866" xlink:to="loc_mar_CostOfRevenueAmountReclassified_019b023a-355c-78ac-815a-5c724d4377f9" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:href="mar-20251231.xsd#mar_SignificantAccountingPoliciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SignificantAccountingPoliciesTable_dc3df22c-745c-4ccf-9e8f-a31782d2db0b" xlink:href="mar-20251231.xsd#mar_SignificantAccountingPoliciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_mar_SignificantAccountingPoliciesTable_dc3df22c-745c-4ccf-9e8f-a31782d2db0b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019bdcaa-ca4a-7554-98b8-906e81ec7a65" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_SignificantAccountingPoliciesTable_dc3df22c-745c-4ccf-9e8f-a31782d2db0b" xlink:to="loc_srt_ProductOrServiceAxis_019bdcaa-ca4a-7554-98b8-906e81ec7a65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019bdcaa-ca4a-7554-98b8-906e81ec7a65_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019bdcaa-ca4a-7554-98b8-906e81ec7a65" xlink:to="loc_srt_ProductsAndServicesDomain_019bdcaa-ca4a-7554-98b8-906e81ec7a65_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019bdcaa-ca4a-7fe5-8a09-6b6c87971081" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019bdcaa-ca4a-7554-98b8-906e81ec7a65" xlink:to="loc_srt_ProductsAndServicesDomain_019bdcaa-ca4a-7fe5-8a09-6b6c87971081" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ContractServicesExcludingLoyaltyProgramMember_019bdcaa-ca4a-7e92-902b-e8cec33af49c" xlink:href="mar-20251231.xsd#mar_ContractServicesExcludingLoyaltyProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019bdcaa-ca4a-7fe5-8a09-6b6c87971081" xlink:to="loc_mar_ContractServicesExcludingLoyaltyProgramMember_019bdcaa-ca4a-7e92-902b-e8cec33af49c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LoyaltyProgramMember_019bdcaa-fab3-758b-a53a-be53c791d74c" xlink:href="mar-20251231.xsd#mar_LoyaltyProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019bdcaa-ca4a-7fe5-8a09-6b6c87971081" xlink:to="loc_mar_LoyaltyProgramMember_019bdcaa-fab3-758b-a53a-be53c791d74c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAxis_019bdcab-6387-7d22-a147-609e91ba6292" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_SignificantAccountingPoliciesTable_dc3df22c-745c-4ccf-9e8f-a31782d2db0b" xlink:to="loc_us-gaap_CapitalizedContractCostAxis_019bdcab-6387-7d22-a147-609e91ba6292" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_019bdcab-6387-7d22-a147-609e91ba6292_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_019bdcab-6387-7d22-a147-609e91ba6292" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_019bdcab-6387-7d22-a147-609e91ba6292_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_019bdcab-6387-7e9a-9d86-b6871f56b4cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_019bdcab-6387-7d22-a147-609e91ba6292" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_019bdcab-6387-7e9a-9d86-b6871f56b4cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CostsIncurredtoFulfillContractsMember_019bdcab-6387-7556-98df-88ac2b657436" xlink:href="mar-20251231.xsd#mar_CostsIncurredtoFulfillContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_019bdcab-6387-7e9a-9d86-b6871f56b4cf" xlink:to="loc_mar_CostsIncurredtoFulfillContractsMember_019bdcab-6387-7556-98df-88ac2b657436" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_019bdcac-a4dd-7e7b-ad6e-7a6076e93fcb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_SignificantAccountingPoliciesTable_dc3df22c-745c-4ccf-9e8f-a31782d2db0b" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_019bdcac-a4dd-7e7b-ad6e-7a6076e93fcb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019bdcac-a4dd-7e7b-ad6e-7a6076e93fcb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019bdcac-a4dd-7e7b-ad6e-7a6076e93fcb" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019bdcac-a4dd-7e7b-ad6e-7a6076e93fcb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019bdcac-a4dd-7143-ba21-481c92650d4f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019bdcac-a4dd-7e7b-ad6e-7a6076e93fcb" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019bdcac-a4dd-7143-ba21-481c92650d4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_019bdcac-a4dd-751f-b4f7-a5302af684d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019bdcac-a4dd-7143-ba21-481c92650d4f" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_019bdcac-a4dd-751f-b4f7-a5302af684d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_019bdcac-a4dd-7ffd-88e5-96f174a48bd2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_SignificantAccountingPoliciesTable_dc3df22c-745c-4ccf-9e8f-a31782d2db0b" xlink:to="loc_us-gaap_ValuationTechniqueAxis_019bdcac-a4dd-7ffd-88e5-96f174a48bd2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019bdcac-a4dd-7ffd-88e5-96f174a48bd2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019bdcac-a4dd-7ffd-88e5-96f174a48bd2" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019bdcac-a4dd-7ffd-88e5-96f174a48bd2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019bdcac-a4dd-7e08-8082-0d5c3c39e7c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019bdcac-a4dd-7ffd-88e5-96f174a48bd2" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019bdcac-a4dd-7e08-8082-0d5c3c39e7c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_019bdcac-a4dd-7d93-ae47-d1ee0d4cb081" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDiscountedCashFlowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_019bdcac-a4dd-7e08-8082-0d5c3c39e7c5" xlink:to="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_019bdcac-a4dd-7d93-ae47-d1ee0d4cb081" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019bdcaa-ca4a-774f-be8b-d7f9bb24b3fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019bdcaa-ca4a-774f-be8b-d7f9bb24b3fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_019bdcaa-ca4a-7c0e-9226-adf32099ffe6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_ContractWithCustomerLiability_019bdcaa-ca4a-7c0e-9226-adf32099ffe6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019bdcaa-ca4a-7a8e-9cca-e7647209bda1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019bdcaa-ca4a-7a8e-9cca-e7647209bda1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice_019bdcaa-fab3-758e-8f2b-bcc8d2df8cb0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice_019bdcaa-fab3-758e-8f2b-bcc8d2df8cb0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNet_019bdcab-6387-7840-923f-cdcf8da7c6db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_CapitalizedContractCostNet_019bdcab-6387-7840-923f-cdcf8da7c6db" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanCostRecognized_019bdcab-8d05-7282-b309-a6c56f104d2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedContributionPlanCostRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_DefinedContributionPlanCostRecognized_019bdcab-8d05-7282-b309-a6c56f104d2c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdvertisingExpense_019bdcab-bc70-78aa-94fc-6e2ff79c52bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdvertisingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_AdvertisingExpense_019bdcab-bc70-78aa-94fc-6e2ff79c52bb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsAndFinancingReceivableAllowanceForCreditLoss_019bdcab-eb2a-7374-b37f-d4710059f677" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsAndFinancingReceivableAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_AccountsAndFinancingReceivableAllowanceForCreditLoss_019bdcab-eb2a-7374-b37f-d4710059f677" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_019bdcac-32cb-7b1a-b28e-ed3a87af8213" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_019bdcac-32cb-7b1a-b28e-ed3a87af8213" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SelfInsuranceReserveMeasurementInput_019bdcac-a4dd-7bec-8af7-54ae88303f66" xlink:href="mar-20251231.xsd#mar_SelfInsuranceReserveMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_mar_SelfInsuranceReserveMeasurementInput_019bdcac-a4dd-7bec-8af7-54ae88303f66" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SelfInsuranceReserveEmployeeBenefitRelated_019c2fe2-3b6c-7114-a04e-1236fa96db16" xlink:href="mar-20251231.xsd#mar_SelfInsuranceReserveEmployeeBenefitRelated"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_mar_SelfInsuranceReserveEmployeeBenefitRelated_019c2fe2-3b6c-7114-a04e-1236fa96db16" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SelfInsuranceReserveCurrent_019bdcac-c7cf-718f-b8f9-15a678b0a816" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SelfInsuranceReserveCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_SelfInsuranceReserveCurrent_019bdcac-c7cf-718f-b8f9-15a678b0a816" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SelfInsuranceReserveNoncurrent_019bdcac-c7cf-73e6-8f5d-31d9693bf2ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SelfInsuranceReserveNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_SignificantAccountingPoliciesLineItems_019bdcaa-ca4a-7fc0-a693-20f01cc8ba02" xlink:to="loc_us-gaap_SelfInsuranceReserveNoncurrent_019bdcac-c7cf-73e6-8f5d-31d9693bf2ab" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/ACQUISITIONDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#ACQUISITIONDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/ACQUISITIONDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionTable_31608db8-258a-44c5-a240-de5c8dd18888" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_us-gaap_AssetAcquisitionTable_31608db8-258a-44c5-a240-de5c8dd18888" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_c7421c67-aeb4-47eb-8319-4ad963003b62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AssetAcquisitionTable_31608db8-258a-44c5-a240-de5c8dd18888" xlink:to="loc_us-gaap_AssetAcquisitionAxis_c7421c67-aeb4-47eb-8319-4ad963003b62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_c7421c67-aeb4-47eb-8319-4ad963003b62_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_c7421c67-aeb4-47eb-8319-4ad963003b62" xlink:to="loc_us-gaap_AssetAcquisitionDomain_c7421c67-aeb4-47eb-8319-4ad963003b62_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_20d9a57d-93f4-44fe-a9a0-71d66419021a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_c7421c67-aeb4-47eb-8319-4ad963003b62" xlink:to="loc_us-gaap_AssetAcquisitionDomain_20d9a57d-93f4-44fe-a9a0-71d66419021a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CitizenMBrandMember_bb4b22c6-a3a0-4967-9bf6-011cd4ca5f3b" xlink:href="mar-20251231.xsd#mar_CitizenMBrandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_20d9a57d-93f4-44fe-a9a0-71d66419021a" xlink:to="loc_mar_CitizenMBrandMember_bb4b22c6-a3a0-4967-9bf6-011cd4ca5f3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferred_e00734e2-d68f-4eb5-b465-923d61bdc129" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferred_e00734e2-d68f-4eb5-b465-923d61bdc129" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_AssetAcquisitionContingentConsiderationRangeOfOutcomesMaximum_a0f86af9-1887-488e-8412-0193a1c17a11" xlink:href="mar-20251231.xsd#mar_AssetAcquisitionContingentConsiderationRangeOfOutcomesMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_mar_AssetAcquisitionContingentConsiderationRangeOfOutcomesMaximum_a0f86af9-1887-488e-8412-0193a1c17a11" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_AssetAcquisitionNumberOfHotelsTbBeAddedToPortfolios_3c0aae59-fb53-435c-87ab-19a42a84ec2c" xlink:href="mar-20251231.xsd#mar_AssetAcquisitionNumberOfHotelsTbBeAddedToPortfolios"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_mar_AssetAcquisitionNumberOfHotelsTbBeAddedToPortfolios_3c0aae59-fb53-435c-87ab-19a42a84ec2c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_AssetAcquisitionNumberOfHotelRoomsToBeAddedToPortfolios_698c1535-798f-4efc-901d-0e712305a2f0" xlink:href="mar-20251231.xsd#mar_AssetAcquisitionNumberOfHotelRoomsToBeAddedToPortfolios"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_mar_AssetAcquisitionNumberOfHotelRoomsToBeAddedToPortfolios_698c1535-798f-4efc-901d-0e712305a2f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefinitelivedIntangibleAssetsAcquired_238e4664-4326-4238-816a-fd0751a1d6f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefinitelivedIntangibleAssetsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_us-gaap_IndefinitelivedIntangibleAssetsAcquired_238e4664-4326-4238-816a-fd0751a1d6f1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_21576488-3245-429a-971e-a80719e53b99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_21576488-3245-429a-971e-a80719e53b99" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_0f84e5a5-f06a-4a13-b9b2-eaea5882caa9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_65eda25c-eee6-41b2-8ab5-be3cd34ead99" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_0f84e5a5-f06a-4a13-b9b2-eaea5882caa9" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/STOCKBASEDCOMPENSATIONAdditionalInformationDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#STOCKBASEDCOMPENSATIONAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/STOCKBASEDCOMPENSATIONAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f4f6d4c2-f5d6-4338-8a62-5b9dfc212c2a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c750aba-70fc-4bc7-a035-dd8014a4c4bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f4f6d4c2-f5d6-4338-8a62-5b9dfc212c2a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c750aba-70fc-4bc7-a035-dd8014a4c4bc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_ebca05e2-6f84-45e6-8021-f01f89d3c6e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c750aba-70fc-4bc7-a035-dd8014a4c4bc" xlink:to="loc_us-gaap_AwardTypeAxis_ebca05e2-6f84-45e6-8021-f01f89d3c6e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ebca05e2-6f84-45e6-8021-f01f89d3c6e9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_ebca05e2-6f84-45e6-8021-f01f89d3c6e9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ebca05e2-6f84-45e6-8021-f01f89d3c6e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cbda67e1-adb6-4d58-b81f-e9c508f82ca6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_ebca05e2-6f84-45e6-8021-f01f89d3c6e9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cbda67e1-adb6-4d58-b81f-e9c508f82ca6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_a7953da4-c619-47c5-9209-ea21cdaa7a77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cbda67e1-adb6-4d58-b81f-e9c508f82ca6" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_a7953da4-c619-47c5-9209-ea21cdaa7a77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_5fd09af0-a938-4476-8c26-9493c3d1f63b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f4f6d4c2-f5d6-4338-8a62-5b9dfc212c2a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_5fd09af0-a938-4476-8c26-9493c3d1f63b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_0634b151-cbdc-47d0-bbe1-ef75a6012e9f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f4f6d4c2-f5d6-4338-8a62-5b9dfc212c2a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_0634b151-cbdc-47d0-bbe1-ef75a6012e9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognized_ae0be46a-5703-4f76-a663-21616867053c" xlink:href="mar-20251231.xsd#mar_ShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f4f6d4c2-f5d6-4338-8a62-5b9dfc212c2a" xlink:to="loc_mar_ShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognized_ae0be46a-5703-4f76-a663-21616867053c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_0084316c-0b0f-4fcd-8e2c-88756b4e1a3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f4f6d4c2-f5d6-4338-8a62-5b9dfc212c2a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_0084316c-0b0f-4fcd-8e2c-88756b4e1a3a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_ee1d22b7-8e5b-4916-8da7-231f740be369" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f4f6d4c2-f5d6-4338-8a62-5b9dfc212c2a" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_ee1d22b7-8e5b-4916-8da7-231f740be369" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/STOCKBASEDCOMPENSATIONScheduleofAdditionalInformationonRSUsDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#STOCKBASEDCOMPENSATIONScheduleofAdditionalInformationonRSUsDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/STOCKBASEDCOMPENSATIONScheduleofAdditionalInformationonRSUsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_279059fb-6245-49fe-9a1b-6318568a4318" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_55f41381-b2b6-4467-8648-0a23e0c60b31" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_279059fb-6245-49fe-9a1b-6318568a4318" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_55f41381-b2b6-4467-8648-0a23e0c60b31" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_0c35073f-90dc-429f-9043-84207ab59a03" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_55f41381-b2b6-4467-8648-0a23e0c60b31" xlink:to="loc_us-gaap_AwardTypeAxis_0c35073f-90dc-429f-9043-84207ab59a03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c35073f-90dc-429f-9043-84207ab59a03_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_0c35073f-90dc-429f-9043-84207ab59a03" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c35073f-90dc-429f-9043-84207ab59a03_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_51b5e60c-1e76-4079-b383-81554ae54abc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_0c35073f-90dc-429f-9043-84207ab59a03" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_51b5e60c-1e76-4079-b383-81554ae54abc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_4506a544-f01c-48ad-a291-21989bdd3c84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_51b5e60c-1e76-4079-b383-81554ae54abc" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_4506a544-f01c-48ad-a291-21989bdd3c84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_6865ba80-b829-4605-9967-c933596385a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_279059fb-6245-49fe-9a1b-6318568a4318" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_6865ba80-b829-4605-9967-c933596385a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_e0e9a4f7-6a58-4d00-bdaf-af66c4900c4c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_279059fb-6245-49fe-9a1b-6318568a4318" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_e0e9a4f7-6a58-4d00-bdaf-af66c4900c4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsConvertedAndDistributedIntrinsicValue_076cf126-7618-4aaf-a8df-f4ee4f1d9eec" xlink:href="mar-20251231.xsd#mar_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsConvertedAndDistributedIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_279059fb-6245-49fe-9a1b-6318568a4318" xlink:to="loc_mar_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsConvertedAndDistributedIntrinsicValue_076cf126-7618-4aaf-a8df-f4ee4f1d9eec" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/STOCKBASEDCOMPENSATIONScheduleofChangesinOutstandingRSUGrantsDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#STOCKBASEDCOMPENSATIONScheduleofChangesinOutstandingRSUGrantsDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/STOCKBASEDCOMPENSATIONScheduleofChangesinOutstandingRSUGrantsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a72095f4-67b4-48ce-8de6-830da6598090" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4566238f-5fe6-4384-9e96-ca17afa242bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a72095f4-67b4-48ce-8de6-830da6598090" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4566238f-5fe6-4384-9e96-ca17afa242bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_3ab8b82f-66a2-4fc7-9687-8aa06bbd0c36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4566238f-5fe6-4384-9e96-ca17afa242bb" xlink:to="loc_us-gaap_AwardTypeAxis_3ab8b82f-66a2-4fc7-9687-8aa06bbd0c36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_3ab8b82f-66a2-4fc7-9687-8aa06bbd0c36_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_3ab8b82f-66a2-4fc7-9687-8aa06bbd0c36" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_3ab8b82f-66a2-4fc7-9687-8aa06bbd0c36_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_31cd6013-ea40-446c-9d05-d7f5ebdab68d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_3ab8b82f-66a2-4fc7-9687-8aa06bbd0c36" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_31cd6013-ea40-446c-9d05-d7f5ebdab68d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_df735ba7-849d-4826-b3c7-546670df14c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_31cd6013-ea40-446c-9d05-d7f5ebdab68d" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_df735ba7-849d-4826-b3c7-546670df14c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5c604f08-8239-4149-92b5-fd1bb665cc92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a72095f4-67b4-48ce-8de6-830da6598090" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5c604f08-8239-4149-92b5-fd1bb665cc92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_2fbfbb4f-28ef-46d7-afae-05b0618d9bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5c604f08-8239-4149-92b5-fd1bb665cc92" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_2fbfbb4f-28ef-46d7-afae-05b0618d9bbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_d6fe4862-ef91-498d-a4b0-128e9881b966" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5c604f08-8239-4149-92b5-fd1bb665cc92" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_d6fe4862-ef91-498d-a4b0-128e9881b966" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_9af10e1c-82a6-4338-b395-2b20fc5ce2fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5c604f08-8239-4149-92b5-fd1bb665cc92" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_9af10e1c-82a6-4338-b395-2b20fc5ce2fd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_3656e9b9-9a9f-4a24-94b1-d032e0b61209" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_5c604f08-8239-4149-92b5-fd1bb665cc92" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_3656e9b9-9a9f-4a24-94b1-d032e0b61209" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_493c544c-3b63-4549-b7e3-f3fdb62a9885" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_8878f47c-47a3-4b1b-b9a3-8770bad485e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a72095f4-67b4-48ce-8de6-830da6598090" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_8878f47c-47a3-4b1b-b9a3-8770bad485e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_7249279c-42ef-4fea-bdfb-8b96c1a9e480" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_8878f47c-47a3-4b1b-b9a3-8770bad485e7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_7249279c-42ef-4fea-bdfb-8b96c1a9e480" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f94b9a1d-50da-4e9c-a0f7-f7fb95fe50e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_8878f47c-47a3-4b1b-b9a3-8770bad485e7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f94b9a1d-50da-4e9c-a0f7-f7fb95fe50e7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_efba4b06-0fd3-48f6-9e12-50c58ee4b4ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_8878f47c-47a3-4b1b-b9a3-8770bad485e7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_efba4b06-0fd3-48f6-9e12-50c58ee4b4ca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_cf98e549-e07e-4a7b-8e84-938800c8dbd2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_8878f47c-47a3-4b1b-b9a3-8770bad485e7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_cf98e549-e07e-4a7b-8e84-938800c8dbd2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_33c9506a-a15b-4a49-bcba-2f757e66f3c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/INCOMETAXESScheduleofReconciliationoftheUSStatutoryTaxRatetoEffectiveIncomeTaxRateDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#INCOMETAXESScheduleofReconciliationoftheUSStatutoryTaxRatetoEffectiveIncomeTaxRateDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/INCOMETAXESScheduleofReconciliationoftheUSStatutoryTaxRatetoEffectiveIncomeTaxRateDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019bfd5f-c8a7-722b-9c77-c2bd2d69b5c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019bfd5f-c8a7-7ad7-ae89-ce0762bb2943" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019bfd5f-c8a7-722b-9c77-c2bd2d69b5c5" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019bfd5f-c8a7-7ad7-ae89-ce0762bb2943" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5f-c8a7-78c3-a688-05c40709de7d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019bfd5f-c8a7-7ad7-ae89-ce0762bb2943" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5f-c8a7-78c3-a688-05c40709de7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5f-c8a7-78c3-a688-05c40709de7d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5f-c8a7-78c3-a688-05c40709de7d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5f-c8a7-78c3-a688-05c40709de7d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5f-c8a7-7331-9de5-755e0ab5c712" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5f-c8a7-78c3-a688-05c40709de7d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5f-c8a7-7331-9de5-755e0ab5c712" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_019c0fda-ea78-7af2-a073-8500160b75a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5f-c8a7-7331-9de5-755e0ab5c712" xlink:to="loc_us-gaap_DomesticCountryMember_019c0fda-ea78-7af2-a073-8500160b75a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019c0fde-b8fd-70ba-ada4-fe595f609324" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticCountryMember_019c0fda-ea78-7af2-a073-8500160b75a4" xlink:to="loc_country_US_019c0fde-b8fd-70ba-ada4-fe595f609324" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_019c43f1-a796-7e16-9856-7962598ce5cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5f-c8a7-7331-9de5-755e0ab5c712" xlink:to="loc_us-gaap_ForeignCountryMember_019c43f1-a796-7e16-9856-7962598ce5cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_019c43f0-fb33-7568-af6a-ea7b5d01eb39" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c43f1-a796-7e16-9856-7962598ce5cb" xlink:to="loc_country_CA_019c43f0-fb33-7568-af6a-ea7b5d01eb39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019bfd5f-c8a7-722b-9c77-c2bd2d69b5c5" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_6c87a380-83b4-4fcb-a1b3-3a73007427f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_6c87a380-83b4-4fcb-a1b3-3a73007427f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxCreditsForeign_019c0fd4-3279-7ec9-8863-b04a93a38c7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationTaxCreditsForeign"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxCreditsForeign_019c0fd4-3279-7ec9-8863-b04a93a38c7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderOtherAmount_019b01ea-64fb-7e7f-a180-164d7064678e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderOtherAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderOtherAmount_019b01ea-64fb-7e7f-a180-164d7064678e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationOtherAdjustments_019bfd51-48a9-7956-ab60-1d78ae85d3e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationOtherAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationOtherAdjustments_019bfd51-48a9-7956-ab60-1d78ae85d3e3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_f79b9197-1f47-48e4-bbbf-8cb1f5405c5c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_f79b9197-1f47-48e4-bbbf-8cb1f5405c5c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderTaxEffectAmount_019b01e9-256a-7eaf-8ae6-f6eaa4910de4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderTaxEffectAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderTaxEffectAmount_019b01e9-256a-7eaf-8ae6-f6eaa4910de4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_019bfd4b-133b-78d9-b961-da660a764018" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_019bfd4b-133b-78d9-b961-da660a764018" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpense_019b01eb-b037-72d0-a80d-b04ba2eca811" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpense_019b01eb-b037-72d0-a80d-b04ba2eca811" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_019c2fe8-b4a5-79c1-a783-2ec724e98aff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_019c2fe8-b4a5-79c1-a783-2ec724e98aff" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxContingencies_019b01ec-4365-7ffa-a4ff-1b499f8a31b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationTaxContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxContingencies_019b01ec-4365-7ffa-a4ff-1b499f8a31b7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_d439c0c1-430f-49db-b609-34b8cd189339" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_4b3bcda1-1205-4155-a499-ea5a634bae36" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_d439c0c1-430f-49db-b609-34b8cd189339" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019bfd5f-c8a7-722b-9c77-c2bd2d69b5c5" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_f754cb64-ee4a-40fe-8259-234c3518ac9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_f754cb64-ee4a-40fe-8259-234c3518ac9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsForeign_019c0fd4-8252-7fdf-96f1-bfb17313c947" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsForeign"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsForeign_019c0fd4-8252-7fdf-96f1-bfb17313c947" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderOtherPercent_019b020d-f7f5-7fca-9023-766a0d1897bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderOtherPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderOtherPercent_019b020d-f7f5-7fca-9023-766a0d1897bb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_019b5900-43e1-70b0-b914-ffcd836a4384" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_019b5900-43e1-70b0-b914-ffcd836a4384" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_1262ebb4-45ff-40de-b4cc-bd0f7b5bb728" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_1262ebb4-45ff-40de-b4cc-bd0f7b5bb728" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderTaxEffectPercent_019b020d-1b36-7d9f-a729-aa5470759f05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderTaxEffectPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationCrossBorderTaxEffectPercent_019b020d-1b36-7d9f-a729-aa5470759f05" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_019b58f8-2d08-7949-9833-233078d71be9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_019b58f8-2d08-7949-9833-233078d71be9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_019bfd54-ef72-73ee-b733-ba33e2dc261e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_019bfd54-ef72-73ee-b733-ba33e2dc261e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_019c2fe8-f3ba-7617-b200-84dd53d953f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_019c2fe8-f3ba-7617-b200-84dd53d953f1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_019b020e-c89e-7191-9f6b-4051f127a10e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_019b020e-c89e-7191-9f6b-4051f127a10e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_fec0ad8f-3097-4c4d-866f-219877c8d83f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_05ea9800-8bd8-4c13-9c0b-3931800ec28e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_fec0ad8f-3097-4c4d-866f-219877c8d83f" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/INCOMETAXESScheduleofIncomeTaxesPaidNetofRefundsReceivedDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#INCOMETAXESScheduleofIncomeTaxesPaidNetofRefundsReceivedDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/INCOMETAXESScheduleofIncomeTaxesPaidNetofRefundsReceivedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019bfd5e-4e52-764d-8d3d-6f37c0b842bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_019bfd5e-4e52-7097-8830-3b3dcdf24e76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019bfd5e-4e52-764d-8d3d-6f37c0b842bb" xlink:to="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_019bfd5e-4e52-7097-8830-3b3dcdf24e76" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5e-4e52-79d4-a5cc-ad810a5585fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_019bfd5e-4e52-7097-8830-3b3dcdf24e76" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5e-4e52-79d4-a5cc-ad810a5585fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5e-4e52-79d4-a5cc-ad810a5585fd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5e-4e52-79d4-a5cc-ad810a5585fd" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5e-4e52-79d4-a5cc-ad810a5585fd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5e-4e52-7e00-b332-71f2de11b1e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019bfd5e-4e52-79d4-a5cc-ad810a5585fd" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5e-4e52-7e00-b332-71f2de11b1e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CH_019bfd5e-4e52-7838-97e0-fd906421a705" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_CH"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5e-4e52-7e00-b332-71f2de11b1e9" xlink:to="loc_country_CH_019bfd5e-4e52-7838-97e0-fd906421a705" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignTaxJurisdictionOtherMember_019bfd5e-4e52-7989-8778-3450a8a6049a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignTaxJurisdictionOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019bfd5e-4e52-7e00-b332-71f2de11b1e9" xlink:to="loc_us-gaap_ForeignTaxJurisdictionOtherMember_019bfd5e-4e52-7989-8778-3450a8a6049a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidFederalAfterRefundReceived_019bfd5e-4e52-75a9-a572-18bf76b76652" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidFederalAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019bfd5e-4e52-764d-8d3d-6f37c0b842bb" xlink:to="loc_us-gaap_IncomeTaxPaidFederalAfterRefundReceived_019bfd5e-4e52-75a9-a572-18bf76b76652" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_019bfd5e-4e52-7d3a-8f94-82a44e799df3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019bfd5e-4e52-764d-8d3d-6f37c0b842bb" xlink:to="loc_us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_019bfd5e-4e52-7d3a-8f94-82a44e799df3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceived_019bfd5e-4e52-7c1f-8016-dfaac8b4389e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidForeignAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019bfd5e-4e52-764d-8d3d-6f37c0b842bb" xlink:to="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceived_019bfd5e-4e52-7c1f-8016-dfaac8b4389e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_019bfd5e-4e52-7e29-b3aa-d8779e569821" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019bfd5e-4e52-764d-8d3d-6f37c0b842bb" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_019bfd5e-4e52-7e29-b3aa-d8779e569821" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/COMMITMENTSANDCONTINGENCIESAdditionalInformationDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#COMMITMENTSANDCONTINGENCIESAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/COMMITMENTSANDCONTINGENCIESAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:href="mar-20251231.xsd#mar_CommitmentsAndContingenciesDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CommitmentsAndContingenciesDisclosureTable_599a2556-571a-4d77-b0e3-348bcc242588" xlink:href="mar-20251231.xsd#mar_CommitmentsAndContingenciesDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:to="loc_mar_CommitmentsAndContingenciesDisclosureTable_599a2556-571a-4d77-b0e3-348bcc242588" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b24591dc-145e-4e10-81f4-cfe7a086b20e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureTable_599a2556-571a-4d77-b0e3-348bcc242588" xlink:to="loc_srt_RangeAxis_b24591dc-145e-4e10-81f4-cfe7a086b20e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b24591dc-145e-4e10-81f4-cfe7a086b20e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b24591dc-145e-4e10-81f4-cfe7a086b20e" xlink:to="loc_srt_RangeMember_b24591dc-145e-4e10-81f4-cfe7a086b20e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_10a06a0a-cd59-4005-949e-ba76df4eb230" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b24591dc-145e-4e10-81f4-cfe7a086b20e" xlink:to="loc_srt_RangeMember_10a06a0a-cd59-4005-949e-ba76df4eb230" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_0d950c8c-3a5f-49b5-8d94-f5dddeb40708" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_10a06a0a-cd59-4005-949e-ba76df4eb230" xlink:to="loc_srt_MinimumMember_0d950c8c-3a5f-49b5-8d94-f5dddeb40708" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_7de541e4-019e-4933-afb6-2ed5e1335f9a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_10a06a0a-cd59-4005-949e-ba76df4eb230" xlink:to="loc_srt_MaximumMember_7de541e4-019e-4933-afb6-2ed5e1335f9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_0c2b549e-52c8-4401-b74d-7ecefe87bc4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureTable_599a2556-571a-4d77-b0e3-348bcc242588" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_0c2b549e-52c8-4401-b74d-7ecefe87bc4a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_0c2b549e-52c8-4401-b74d-7ecefe87bc4a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_0c2b549e-52c8-4401-b74d-7ecefe87bc4a" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_0c2b549e-52c8-4401-b74d-7ecefe87bc4a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_6ec9f716-190c-4e3f-9c29-c8e2ede21005" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_0c2b549e-52c8-4401-b74d-7ecefe87bc4a" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_6ec9f716-190c-4e3f-9c29-c8e2ede21005" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_25d47c2a-016a-4098-a2e4-481fbdb248e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_6ec9f716-190c-4e3f-9c29-c8e2ede21005" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_25d47c2a-016a-4098-a2e4-481fbdb248e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_60df0b8f-69f5-4126-8334-bfac6fa72947" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoncurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_6ec9f716-190c-4e3f-9c29-c8e2ede21005" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_60df0b8f-69f5-4126-8334-bfac6fa72947" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LossContingenciesBySecondaryNatureOfContingencyAxis_57a2cde7-a60a-4e27-bfdc-a954e3e656a8" xlink:href="mar-20251231.xsd#mar_LossContingenciesBySecondaryNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureTable_599a2556-571a-4d77-b0e3-348bcc242588" xlink:to="loc_mar_LossContingenciesBySecondaryNatureOfContingencyAxis_57a2cde7-a60a-4e27-bfdc-a954e3e656a8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LossContingenciesBySecondaryNatureOfContingencyDomain_57a2cde7-a60a-4e27-bfdc-a954e3e656a8_default" xlink:href="mar-20251231.xsd#mar_LossContingenciesBySecondaryNatureOfContingencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_mar_LossContingenciesBySecondaryNatureOfContingencyAxis_57a2cde7-a60a-4e27-bfdc-a954e3e656a8" xlink:to="loc_mar_LossContingenciesBySecondaryNatureOfContingencyDomain_57a2cde7-a60a-4e27-bfdc-a954e3e656a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LossContingenciesBySecondaryNatureOfContingencyDomain_11a0b858-f1e7-49b9-ac89-e7459fdfe726" xlink:href="mar-20251231.xsd#mar_LossContingenciesBySecondaryNatureOfContingencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_mar_LossContingenciesBySecondaryNatureOfContingencyAxis_57a2cde7-a60a-4e27-bfdc-a954e3e656a8" xlink:to="loc_mar_LossContingenciesBySecondaryNatureOfContingencyDomain_11a0b858-f1e7-49b9-ac89-e7459fdfe726" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_NotYetInEffectConditionMember_b14cb925-2ba8-443f-af74-8c0fb18043e4" xlink:href="mar-20251231.xsd#mar_NotYetInEffectConditionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_LossContingenciesBySecondaryNatureOfContingencyDomain_11a0b858-f1e7-49b9-ac89-e7459fdfe726" xlink:to="loc_mar_NotYetInEffectConditionMember_b14cb925-2ba8-443f-af74-8c0fb18043e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_5a410952-09ae-43c0-b1b6-eef71f8bfdd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureTable_599a2556-571a-4d77-b0e3-348bcc242588" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_5a410952-09ae-43c0-b1b6-eef71f8bfdd9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_5a410952-09ae-43c0-b1b6-eef71f8bfdd9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_5a410952-09ae-43c0-b1b6-eef71f8bfdd9" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_5a410952-09ae-43c0-b1b6-eef71f8bfdd9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_012cb593-28a7-4ae0-b36e-0affaa13fd5c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_5a410952-09ae-43c0-b1b6-eef71f8bfdd9" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_012cb593-28a7-4ae0-b36e-0affaa13fd5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_GuaranteeOperatingProfitMember_a3fc2b41-55e3-47d7-b608-8b26cff1d0ec" xlink:href="mar-20251231.xsd#mar_GuaranteeOperatingProfitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_012cb593-28a7-4ae0-b36e-0affaa13fd5c" xlink:to="loc_mar_GuaranteeOperatingProfitMember_a3fc2b41-55e3-47d7-b608-8b26cff1d0ec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_a7a7e813-a158-4de3-b7e3-c5eaca878933" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureTable_599a2556-571a-4d77-b0e3-348bcc242588" xlink:to="loc_srt_LitigationCaseAxis_a7a7e813-a158-4de3-b7e3-c5eaca878933" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_a7a7e813-a158-4de3-b7e3-c5eaca878933_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_a7a7e813-a158-4de3-b7e3-c5eaca878933" xlink:to="loc_srt_LitigationCaseTypeDomain_a7a7e813-a158-4de3-b7e3-c5eaca878933_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_9135cd58-0e3a-4f0c-8be0-a1e00333bf6a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_a7a7e813-a158-4de3-b7e3-c5eaca878933" xlink:to="loc_srt_LitigationCaseTypeDomain_9135cd58-0e3a-4f0c-8be0-a1e00333bf6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ClassActionLawsuitsRelatedToDataSecurityIncidentMember_58f403f0-b6bc-4985-9c03-0aedcbdb857e" xlink:href="mar-20251231.xsd#mar_ClassActionLawsuitsRelatedToDataSecurityIncidentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_9135cd58-0e3a-4f0c-8be0-a1e00333bf6a" xlink:to="loc_mar_ClassActionLawsuitsRelatedToDataSecurityIncidentMember_58f403f0-b6bc-4985-9c03-0aedcbdb857e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_GuaranteeObligationTerm_cb5b9922-1af1-44d2-bd84-168f8639279c" xlink:href="mar-20251231.xsd#mar_GuaranteeObligationTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:to="loc_mar_GuaranteeObligationTerm_cb5b9922-1af1-44d2-bd84-168f8639279c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_771afc21-4619-4274-87d1-11a97b2a1009" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_771afc21-4619-4274-87d1-11a97b2a1009" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsMaximumExposure_ba25e742-8fd1-4930-ab63-21c32dcd56a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsMaximumExposure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:to="loc_us-gaap_GuaranteeObligationsMaximumExposure_ba25e742-8fd1-4930-ab63-21c32dcd56a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_ec012924-f35c-413f-97ff-2177cbabe315" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_ec012924-f35c-413f-97ff-2177cbabe315" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SuretyBonds_f3e0121d-28e3-43d1-9350-e483ff77919d" xlink:href="mar-20251231.xsd#mar_SuretyBonds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:to="loc_mar_SuretyBonds_f3e0121d-28e3-43d1-9350-e483ff77919d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_b0f75ffb-11ce-402f-9b5f-133405238730" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyNewClaimsFiledNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_3c24973a-9137-41a0-9e32-51c6a1cc981b" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_b0f75ffb-11ce-402f-9b5f-133405238730" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_dc041610-6041-4812-9dee-89ce7f3e047e" xlink:href="mar-20251231.xsd#mar_CommitmentsAndContingenciesDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CommitmentsAndContingenciesDisclosureTable_f87bc7cf-8e48-44f1-9a82-012767cb84b4" xlink:href="mar-20251231.xsd#mar_CommitmentsAndContingenciesDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_dc041610-6041-4812-9dee-89ce7f3e047e" xlink:to="loc_mar_CommitmentsAndContingenciesDisclosureTable_f87bc7cf-8e48-44f1-9a82-012767cb84b4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_3bf9f292-abc0-4793-a744-079498070413" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureTable_f87bc7cf-8e48-44f1-9a82-012767cb84b4" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_3bf9f292-abc0-4793-a744-079498070413" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_3bf9f292-abc0-4793-a744-079498070413_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_3bf9f292-abc0-4793-a744-079498070413" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_3bf9f292-abc0-4793-a744-079498070413_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_73ebdcb0-45ed-41ec-b085-74f55a278cde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_3bf9f292-abc0-4793-a744-079498070413" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_73ebdcb0-45ed-41ec-b085-74f55a278cde" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeOfIndebtednessOfOthersMember_01fb2781-f13d-4b97-86df-5b70ea85f268" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeOfIndebtednessOfOthersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_73ebdcb0-45ed-41ec-b085-74f55a278cde" xlink:to="loc_us-gaap_GuaranteeOfIndebtednessOfOthersMember_01fb2781-f13d-4b97-86df-5b70ea85f268" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_GuaranteeOperatingProfitMember_ea950afe-5a2d-4ca1-a2ce-98ee08ee26d5" xlink:href="mar-20251231.xsd#mar_GuaranteeOperatingProfitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_73ebdcb0-45ed-41ec-b085-74f55a278cde" xlink:to="loc_mar_GuaranteeOperatingProfitMember_ea950afe-5a2d-4ca1-a2ce-98ee08ee26d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeTypeOtherMember_30cd624d-2236-4482-8b45-6df878a2616b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeTypeOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_73ebdcb0-45ed-41ec-b085-74f55a278cde" xlink:to="loc_us-gaap_GuaranteeTypeOtherMember_30cd624d-2236-4482-8b45-6df878a2616b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsMaximumExposure_3937dfe8-2531-4498-8003-00936d515834" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsMaximumExposure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_dc041610-6041-4812-9dee-89ce7f3e047e" xlink:to="loc_us-gaap_GuaranteeObligationsMaximumExposure_3937dfe8-2531-4498-8003-00936d515834" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_b93cf445-035e-4896-95f9-4da5000c63b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_mar_CommitmentsAndContingenciesDisclosureLineItems_dc041610-6041-4812-9dee-89ce7f3e047e" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_b93cf445-035e-4896-95f9-4da5000c63b0" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/LEASESAdditionalInformationDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#LEASESAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/LEASESAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_464efd83-3656-4c9c-92e0-9f7297ba0b25" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bf899c16-82f9-483e-b96b-3f4bde3a0c64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_464efd83-3656-4c9c-92e0-9f7297ba0b25" xlink:to="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bf899c16-82f9-483e-b96b-3f4bde3a0c64" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_53f53be6-94db-4caa-bc39-f7e01e244d4f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bf899c16-82f9-483e-b96b-3f4bde3a0c64" xlink:to="loc_srt_RangeAxis_53f53be6-94db-4caa-bc39-f7e01e244d4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_53f53be6-94db-4caa-bc39-f7e01e244d4f_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_53f53be6-94db-4caa-bc39-f7e01e244d4f" xlink:to="loc_srt_RangeMember_53f53be6-94db-4caa-bc39-f7e01e244d4f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_34484438-6853-4ddb-9bae-8a6c8ce1aa2a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_53f53be6-94db-4caa-bc39-f7e01e244d4f" xlink:to="loc_srt_RangeMember_34484438-6853-4ddb-9bae-8a6c8ce1aa2a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_a0fa9d89-66da-4fe8-be01-8c75f344979e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_34484438-6853-4ddb-9bae-8a6c8ce1aa2a" xlink:to="loc_srt_MinimumMember_a0fa9d89-66da-4fe8-be01-8c75f344979e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_31874c64-a1c9-4df2-9b52-556c6c9e4aec" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_34484438-6853-4ddb-9bae-8a6c8ce1aa2a" xlink:to="loc_srt_MaximumMember_31874c64-a1c9-4df2-9b52-556c6c9e4aec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LesseeOperatingAndFinanceLeaseTermOfContract_47608d12-63dc-4bfe-8103-e369cd831316" xlink:href="mar-20251231.xsd#mar_LesseeOperatingAndFinanceLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_464efd83-3656-4c9c-92e0-9f7297ba0b25" xlink:to="loc_mar_LesseeOperatingAndFinanceLeaseTermOfContract_47608d12-63dc-4bfe-8103-e369cd831316" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LesseeOperatingAndFinanceLeaseNumberOfOptionsForRenewal_47b5430f-9b88-47f8-9f0e-396b48cbc27c" xlink:href="mar-20251231.xsd#mar_LesseeOperatingAndFinanceLeaseNumberOfOptionsForRenewal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_464efd83-3656-4c9c-92e0-9f7297ba0b25" xlink:to="loc_mar_LesseeOperatingAndFinanceLeaseNumberOfOptionsForRenewal_47b5430f-9b88-47f8-9f0e-396b48cbc27c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_LesseeOperatingAndFinanceLeaseRenewalTerm_c99c3ff3-70d6-4d6d-abe6-b13612691494" xlink:href="mar-20251231.xsd#mar_LesseeOperatingAndFinanceLeaseRenewalTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_464efd83-3656-4c9c-92e0-9f7297ba0b25" xlink:to="loc_mar_LesseeOperatingAndFinanceLeaseRenewalTerm_c99c3ff3-70d6-4d6d-abe6-b13612691494" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/LONGTERMDEBTScheduleofDetailonLongtermDebtBalancesDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#LONGTERMDEBTScheduleofDetailonLongtermDebtBalancesDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/LONGTERMDEBTScheduleofDetailonLongtermDebtBalancesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_a72e605d-9cc9-4b35-af98-cdbdffbd4460" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_DebtInstrumentTable_a72e605d-9cc9-4b35-af98-cdbdffbd4460" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_1df37117-6bb8-4598-a888-eddfdcfc8c0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_a72e605d-9cc9-4b35-af98-cdbdffbd4460" xlink:to="loc_us-gaap_DebtInstrumentAxis_1df37117-6bb8-4598-a888-eddfdcfc8c0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1df37117-6bb8-4598-a888-eddfdcfc8c0d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_1df37117-6bb8-4598-a888-eddfdcfc8c0d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1df37117-6bb8-4598-a888-eddfdcfc8c0d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_1df37117-6bb8-4598-a888-eddfdcfc8c0d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesPSeniorNotesMember_81229055-5fb0-4252-b80e-0060730bf87d" xlink:href="mar-20251231.xsd#mar_SeriesPSeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesPSeniorNotesMember_81229055-5fb0-4252-b80e-0060730bf87d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesRNotesMember_5ec248bb-e9cb-431a-b6dd-f7f6e1b52ec4" xlink:href="mar-20251231.xsd#mar_SeriesRNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesRNotesMember_5ec248bb-e9cb-431a-b6dd-f7f6e1b52ec4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesVNotesMember_ce03235e-2f93-4726-b36f-55479eb7d2f9" xlink:href="mar-20251231.xsd#mar_SeriesVNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesVNotesMember_ce03235e-2f93-4726-b36f-55479eb7d2f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesWNotesMember_dfb5f8fd-3589-4836-9f4f-d21d48a2388c" xlink:href="mar-20251231.xsd#mar_SeriesWNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesWNotesMember_dfb5f8fd-3589-4836-9f4f-d21d48a2388c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesXNotesMember_409af072-417a-44a6-8f2b-8cab9a136ad8" xlink:href="mar-20251231.xsd#mar_SeriesXNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesXNotesMember_409af072-417a-44a6-8f2b-8cab9a136ad8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesAANotesMember_d726102a-d306-487e-9f2c-a03f40435db8" xlink:href="mar-20251231.xsd#mar_SeriesAANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesAANotesMember_d726102a-d306-487e-9f2c-a03f40435db8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesEENotesMember_6721400d-8b11-427e-8e68-7e0b3eac99ee" xlink:href="mar-20251231.xsd#mar_SeriesEENotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesEENotesMember_6721400d-8b11-427e-8e68-7e0b3eac99ee" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesFFNotesMember_cc4139ed-2044-4b94-b6ce-5d6cb4080771" xlink:href="mar-20251231.xsd#mar_SeriesFFNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesFFNotesMember_cc4139ed-2044-4b94-b6ce-5d6cb4080771" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesGGNotesMember_0fca2e7a-3186-4022-aa77-7504057db852" xlink:href="mar-20251231.xsd#mar_SeriesGGNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesGGNotesMember_0fca2e7a-3186-4022-aa77-7504057db852" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesHHNotesMember_c72fc5d0-0a9e-41bf-b63f-649cb2e078d3" xlink:href="mar-20251231.xsd#mar_SeriesHHNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesHHNotesMember_c72fc5d0-0a9e-41bf-b63f-649cb2e078d3" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesIINotesMember_3c41b147-ae67-4415-a152-99d033522438" xlink:href="mar-20251231.xsd#mar_SeriesIINotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesIINotesMember_3c41b147-ae67-4415-a152-99d033522438" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesJJNotesMember_df7a1932-3f4f-4413-944a-656c7aa54d18" xlink:href="mar-20251231.xsd#mar_SeriesJJNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesJJNotesMember_df7a1932-3f4f-4413-944a-656c7aa54d18" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesKKNotesMember_8547b8c7-c440-43a5-aac3-071f89a3a2c8" xlink:href="mar-20251231.xsd#mar_SeriesKKNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesKKNotesMember_8547b8c7-c440-43a5-aac3-071f89a3a2c8" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesLLNotesMember_9138e995-6614-468b-97a8-2a1881267627" xlink:href="mar-20251231.xsd#mar_SeriesLLNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesLLNotesMember_9138e995-6614-468b-97a8-2a1881267627" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesMMNotesMember_b3d2c328-b84e-47f4-8ee2-63e02fcb17c7" xlink:href="mar-20251231.xsd#mar_SeriesMMNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesMMNotesMember_b3d2c328-b84e-47f4-8ee2-63e02fcb17c7" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesNNNotesMember_b3af8293-00fc-498b-a769-9a1ba0a2a37e" xlink:href="mar-20251231.xsd#mar_SeriesNNNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesNNNotesMember_b3af8293-00fc-498b-a769-9a1ba0a2a37e" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesOONotesMember_f107bcce-6faa-40bf-9e3c-341933c64a4a" xlink:href="mar-20251231.xsd#mar_SeriesOONotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesOONotesMember_f107bcce-6faa-40bf-9e3c-341933c64a4a" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesPPNotesMember_426e5e3b-955b-41a4-b07e-67f816886783" xlink:href="mar-20251231.xsd#mar_SeriesPPNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesPPNotesMember_426e5e3b-955b-41a4-b07e-67f816886783" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesQQNotesMember_fa476bb2-87d6-484a-b338-1b166644b630" xlink:href="mar-20251231.xsd#mar_SeriesQQNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesQQNotesMember_fa476bb2-87d6-484a-b338-1b166644b630" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesRRNotesMember_88a6be4b-aba0-47b2-9c36-ae7ea8cfab57" xlink:href="mar-20251231.xsd#mar_SeriesRRNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesRRNotesMember_88a6be4b-aba0-47b2-9c36-ae7ea8cfab57" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesSSNotesMember_0f762599-f0e7-45b5-9864-70b31f8d2a38" xlink:href="mar-20251231.xsd#mar_SeriesSSNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesSSNotesMember_0f762599-f0e7-45b5-9864-70b31f8d2a38" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesTTNotesMember_bda575ba-2b8b-4176-a7e9-76f9227ac007" xlink:href="mar-20251231.xsd#mar_SeriesTTNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesTTNotesMember_bda575ba-2b8b-4176-a7e9-76f9227ac007" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesUUNotesMember_dc867bdd-4001-4917-a352-658d7ea4f026" xlink:href="mar-20251231.xsd#mar_SeriesUUNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesUUNotesMember_dc867bdd-4001-4917-a352-658d7ea4f026" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesVVNotesMember_c66c020e-2a9e-4620-ac58-35a1c865c116" xlink:href="mar-20251231.xsd#mar_SeriesVVNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7123ab37-77da-4ffa-8688-93d0ced0b5f3" xlink:to="loc_mar_SeriesVVNotesMember_c66c020e-2a9e-4620-ac58-35a1c865c116" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_bdc210a7-d369-48f0-879b-ddb4d0e87f57" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_bdc210a7-d369-48f0-879b-ddb4d0e87f57" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_f8b5253f-5c76-4984-825c-ce70c4e1da52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_f8b5253f-5c76-4984-825c-ce70c4e1da52" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_7f16fe10-d532-441d-85e3-197ac61dc02f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_7f16fe10-d532-441d-85e3-197ac61dc02f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotes_483ccfbb-2778-4902-b89d-a6fe823dd469" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_SeniorNotes_483ccfbb-2778-4902-b89d-a6fe823dd469" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperNoncurrent_bdbcbdf5-8747-4b02-8b85-a8dc5136994b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialPaperNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_CommercialPaperNoncurrent_bdbcbdf5-8747-4b02-8b85-a8dc5136994b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_93054af6-56a4-4de9-be4e-aad39ffc61a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_LineOfCredit_93054af6-56a4-4de9-be4e-aad39ffc61a2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_41870af6-27cb-464a-840c-fd8fe828a3e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_FinanceLeaseLiability_41870af6-27cb-464a-840c-fd8fe828a3e9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_68775710-5443-46cd-8739-8e29239443f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_LongTermDebt_68775710-5443-46cd-8739-8e29239443f2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_d7c00a37-1394-4aef-9e3d-15caedf8ece6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_d7c00a37-1394-4aef-9e3d-15caedf8ece6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_a9fa9900-dbf2-4d3a-97d2-c4c133e3f4f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_a9fa9900-dbf2-4d3a-97d2-c4c133e3f4f7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_c3da48bf-e7ac-41ac-8b0f-8ecdfef5450d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3964a7f0-eb01-482d-8661-90003189c051" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_c3da48bf-e7ac-41ac-8b0f-8ecdfef5450d" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/LONGTERMDEBTAdditionalInformationDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#LONGTERMDEBTAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/LONGTERMDEBTAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_32a42fb0-afa2-4821-ae12-b640a0160fcd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_DebtInstrumentTable_32a42fb0-afa2-4821-ae12-b640a0160fcd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_b92ebd80-07b9-4d7e-aea3-465691546301" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_32a42fb0-afa2-4821-ae12-b640a0160fcd" xlink:to="loc_us-gaap_DebtInstrumentAxis_b92ebd80-07b9-4d7e-aea3-465691546301" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_b92ebd80-07b9-4d7e-aea3-465691546301_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_b92ebd80-07b9-4d7e-aea3-465691546301" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_b92ebd80-07b9-4d7e-aea3-465691546301_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_b92ebd80-07b9-4d7e-aea3-465691546301" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesTTNotesMember_9318c9bd-2000-4f89-b818-491667590420" xlink:href="mar-20251231.xsd#mar_SeriesTTNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:to="loc_mar_SeriesTTNotesMember_9318c9bd-2000-4f89-b818-491667590420" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesUUNotesMember_ee79a884-2773-487f-acb9-866b7bb8fe33" xlink:href="mar-20251231.xsd#mar_SeriesUUNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:to="loc_mar_SeriesUUNotesMember_ee79a884-2773-487f-acb9-866b7bb8fe33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesVVNotesMember_d6870b5d-b7f7-475c-9c2f-6d8397859d5f" xlink:href="mar-20251231.xsd#mar_SeriesVVNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:to="loc_mar_SeriesVVNotesMember_d6870b5d-b7f7-475c-9c2f-6d8397859d5f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesTTUUAndVVNotesMember_1c02948b-f78b-421d-b066-2e8f644c507e" xlink:href="mar-20251231.xsd#mar_SeriesTTUUAndVVNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:to="loc_mar_SeriesTTUUAndVVNotesMember_1c02948b-f78b-421d-b066-2e8f644c507e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesRRNotesMember_92becdfa-d709-4cde-8f45-92e40ad5bddb" xlink:href="mar-20251231.xsd#mar_SeriesRRNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:to="loc_mar_SeriesRRNotesMember_92becdfa-d709-4cde-8f45-92e40ad5bddb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesSSNotesMember_097f80fd-996d-4165-9934-1469d1862fc2" xlink:href="mar-20251231.xsd#mar_SeriesSSNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:to="loc_mar_SeriesSSNotesMember_097f80fd-996d-4165-9934-1469d1862fc2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_SeriesRRAndSSNotesMember_5089c70a-62dc-4973-bd68-3b781411da9b" xlink:href="mar-20251231.xsd#mar_SeriesRRAndSSNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_44f343ba-2737-492a-8498-ae7cda67cdb1" xlink:to="loc_mar_SeriesRRAndSSNotesMember_5089c70a-62dc-4973-bd68-3b781411da9b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_aa026a2d-d709-4e11-9dfe-e766ab1189eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_32a42fb0-afa2-4821-ae12-b640a0160fcd" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_aa026a2d-d709-4e11-9dfe-e766ab1189eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_aa026a2d-d709-4e11-9dfe-e766ab1189eb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_aa026a2d-d709-4e11-9dfe-e766ab1189eb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_aa026a2d-d709-4e11-9dfe-e766ab1189eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_fec32e02-1469-4454-9ddb-b3f7f2827a5a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_aa026a2d-d709-4e11-9dfe-e766ab1189eb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_fec32e02-1469-4454-9ddb-b3f7f2827a5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_c9d9a29b-9550-4799-bd6c-fa5a3c371772" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_fec32e02-1469-4454-9ddb-b3f7f2827a5a" xlink:to="loc_us-gaap_SeniorNotesMember_c9d9a29b-9550-4799-bd6c-fa5a3c371772" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_3f0bd3d3-f2c6-49a4-b185-dce636eee157" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_32a42fb0-afa2-4821-ae12-b640a0160fcd" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_3f0bd3d3-f2c6-49a4-b185-dce636eee157" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_3f0bd3d3-f2c6-49a4-b185-dce636eee157_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_3f0bd3d3-f2c6-49a4-b185-dce636eee157" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_3f0bd3d3-f2c6-49a4-b185-dce636eee157_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_d83c5dd6-aaf4-4bdd-95f4-7383ba0130ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_3f0bd3d3-f2c6-49a4-b185-dce636eee157" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_d83c5dd6-aaf4-4bdd-95f4-7383ba0130ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_0794d96c-7eae-4731-b0af-fbaa6b2bdc37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_d83c5dd6-aaf4-4bdd-95f4-7383ba0130ae" xlink:to="loc_us-gaap_InterestRateSwapMember_0794d96c-7eae-4731-b0af-fbaa6b2bdc37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_28169773-4d14-4950-8f2f-fc1aed2e85d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_28169773-4d14-4950-8f2f-fc1aed2e85d5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_d20dbaa9-e88d-4177-8661-39bd334a9e7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_d20dbaa9-e88d-4177-8661-39bd334a9e7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_1e0e44e8-1e9f-4223-8c44-90eb68f7cd66" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_1e0e44e8-1e9f-4223-8c44-90eb68f7cd66" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_418456c7-1c01-4108-a62b-9911197e005c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_418456c7-1c01-4108-a62b-9911197e005c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_d61e6404-6f4f-4296-b142-414266de62c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeBasisSpreadOnVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_d61e6404-6f4f-4296-b142-414266de62c9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_63f32e61-a679-48c5-adfc-2eaec2b93d85" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_63f32e61-a679-48c5-adfc-2eaec2b93d85" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet_6b206a0f-d2d4-46e8-9d53-111fa92a2a7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_681e2cce-b519-4747-a1c3-f6c23b4454c5" xlink:to="loc_us-gaap_InterestPaidNet_6b206a0f-d2d4-46e8-9d53-111fa92a2a7a" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/INTANGIBLEASSETSANDGOODWILLScheduleofCompositionofAcquiredIntangibleAssetsDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#INTANGIBLEASSETSANDGOODWILLScheduleofCompositionofAcquiredIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/INTANGIBLEASSETSANDGOODWILLScheduleofCompositionofAcquiredIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_8e656a4b-4273-4021-b23f-3d63c280215d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_176453d4-3224-4a65-a4c6-701d59c3aa09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_8e656a4b-4273-4021-b23f-3d63c280215d" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_176453d4-3224-4a65-a4c6-701d59c3aa09" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_c720f0b2-848e-495e-a8c1-fb0c9a422475" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_176453d4-3224-4a65-a4c6-701d59c3aa09" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_c720f0b2-848e-495e-a8c1-fb0c9a422475" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_c720f0b2-848e-495e-a8c1-fb0c9a422475_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_c720f0b2-848e-495e-a8c1-fb0c9a422475" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_c720f0b2-848e-495e-a8c1-fb0c9a422475_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_79d0dc9f-c4d6-48e9-97ed-1651c1bec8b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_c720f0b2-848e-495e-a8c1-fb0c9a422475" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_79d0dc9f-c4d6-48e9-97ed-1651c1bec8b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CostsIncurredtoObtainContractsMember_48b050ee-f532-4a4a-94bc-91cbaeb9b0d2" xlink:href="mar-20251231.xsd#mar_CostsIncurredtoObtainContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_79d0dc9f-c4d6-48e9-97ed-1651c1bec8b1" xlink:to="loc_mar_CostsIncurredtoObtainContractsMember_48b050ee-f532-4a4a-94bc-91cbaeb9b0d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_AcquiredContractsAndOtherMember_b4c2a9ed-e9cd-40c4-8836-cd3f7f9fc87e" xlink:href="mar-20251231.xsd#mar_AcquiredContractsAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_79d0dc9f-c4d6-48e9-97ed-1651c1bec8b1" xlink:to="loc_mar_AcquiredContractsAndOtherMember_b4c2a9ed-e9cd-40c4-8836-cd3f7f9fc87e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_9db21427-8026-42c0-9f2f-fc41bdd7834b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_79d0dc9f-c4d6-48e9-97ed-1651c1bec8b1" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_9db21427-8026-42c0-9f2f-fc41bdd7834b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_3f02d2cb-d8b1-4d72-8f5c-9fbb01fd3fe9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_8e656a4b-4273-4021-b23f-3d63c280215d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_3f02d2cb-d8b1-4d72-8f5c-9fbb01fd3fe9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_607d12ae-c58f-41c7-9169-438f6698a0a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_8e656a4b-4273-4021-b23f-3d63c280215d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_607d12ae-c58f-41c7-9169-438f6698a0a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_70b466d2-e8f3-48da-8f5a-e50e876d4b9c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_8e656a4b-4273-4021-b23f-3d63c280215d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_70b466d2-e8f3-48da-8f5a-e50e876d4b9c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems_b7a09743-86de-4082-bed3-4969bae0ee4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable_1493f296-6b82-4fa6-ab35-9a3096cd3f45" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems_b7a09743-86de-4082-bed3-4969bae0ee4a" xlink:to="loc_us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable_1493f296-6b82-4fa6-ab35-9a3096cd3f45" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_9265dc7b-ff4a-42bc-ab4a-2a56cd564039" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable_1493f296-6b82-4fa6-ab35-9a3096cd3f45" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_9265dc7b-ff4a-42bc-ab4a-2a56cd564039" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_9265dc7b-ff4a-42bc-ab4a-2a56cd564039_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_9265dc7b-ff4a-42bc-ab4a-2a56cd564039" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_9265dc7b-ff4a-42bc-ab4a-2a56cd564039_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_f78fdd79-2587-4ee8-963b-ccc479b854de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_9265dc7b-ff4a-42bc-ab4a-2a56cd564039" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_f78fdd79-2587-4ee8-963b-ccc479b854de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_bbe686b9-c1c2-4d34-994a-f67b0705a149" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_f78fdd79-2587-4ee8-963b-ccc479b854de" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_bbe686b9-c1c2-4d34-994a-f67b0705a149" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_27610f24-b386-4975-a0ac-8fabbec235f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems_b7a09743-86de-4082-bed3-4969bae0ee4a" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_27610f24-b386-4975-a0ac-8fabbec235f6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/INTANGIBLEASSETSANDGOODWILLAdditionalInformationDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#INTANGIBLEASSETSANDGOODWILLAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/INTANGIBLEASSETSANDGOODWILLAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_d275a23c-f823-4684-a022-210f60c267ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_d275a23c-f823-4684-a022-210f60c267ed" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_2e03181f-e563-4ff1-9d86-e714f992ae68" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_d275a23c-f823-4684-a022-210f60c267ed" xlink:to="loc_srt_RangeAxis_2e03181f-e563-4ff1-9d86-e714f992ae68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2e03181f-e563-4ff1-9d86-e714f992ae68_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_2e03181f-e563-4ff1-9d86-e714f992ae68" xlink:to="loc_srt_RangeMember_2e03181f-e563-4ff1-9d86-e714f992ae68_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_0bc32fbe-aac3-428c-ad24-1f6bda6d92ed" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_2e03181f-e563-4ff1-9d86-e714f992ae68" xlink:to="loc_srt_RangeMember_0bc32fbe-aac3-428c-ad24-1f6bda6d92ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_00de6b23-7758-40c4-bcff-f9a1b4fc9ca7" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0bc32fbe-aac3-428c-ad24-1f6bda6d92ed" xlink:to="loc_srt_MinimumMember_00de6b23-7758-40c4-bcff-f9a1b4fc9ca7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_4abf4867-8ba2-4856-92b5-478142942218" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0bc32fbe-aac3-428c-ad24-1f6bda6d92ed" xlink:to="loc_srt_MaximumMember_4abf4867-8ba2-4856-92b5-478142942218" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6286dcdf-b30e-4b50-b41b-fdd318a12137" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_d275a23c-f823-4684-a022-210f60c267ed" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6286dcdf-b30e-4b50-b41b-fdd318a12137" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_6286dcdf-b30e-4b50-b41b-fdd318a12137_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6286dcdf-b30e-4b50-b41b-fdd318a12137" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_6286dcdf-b30e-4b50-b41b-fdd318a12137_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f77b162a-6e3d-4ac2-a207-1c36dc8599f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6286dcdf-b30e-4b50-b41b-fdd318a12137" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f77b162a-6e3d-4ac2-a207-1c36dc8599f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CostsIncurredtoObtainContractsMember_48fa3f73-3e7e-4801-a9ac-69265254f033" xlink:href="mar-20251231.xsd#mar_CostsIncurredtoObtainContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f77b162a-6e3d-4ac2-a207-1c36dc8599f8" xlink:to="loc_mar_CostsIncurredtoObtainContractsMember_48fa3f73-3e7e-4801-a9ac-69265254f033" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_baf9605c-9032-442b-aa38-ead1f8c94bb0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f77b162a-6e3d-4ac2-a207-1c36dc8599f8" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_baf9605c-9032-442b-aa38-ead1f8c94bb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_2d162c61-a3f8-4cea-b2e5-b84b52261231" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_d275a23c-f823-4684-a022-210f60c267ed" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_2d162c61-a3f8-4cea-b2e5-b84b52261231" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_2d162c61-a3f8-4cea-b2e5-b84b52261231_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_2d162c61-a3f8-4cea-b2e5-b84b52261231" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_2d162c61-a3f8-4cea-b2e5-b84b52261231_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_f058d2f0-151a-49bf-a2e5-d917fd059517" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_2d162c61-a3f8-4cea-b2e5-b84b52261231" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_f058d2f0-151a-49bf-a2e5-d917fd059517" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ReimbursedExpensesMember_b85269fd-a1e3-4591-b8b7-46a1a2b9d8bc" xlink:href="mar-20251231.xsd#mar_ReimbursedExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f058d2f0-151a-49bf-a2e5-d917fd059517" xlink:to="loc_mar_ReimbursedExpensesMember_b85269fd-a1e3-4591-b8b7-46a1a2b9d8bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_2b8e1b5d-fc3f-47d0-807f-6b93cb47f6bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_2b8e1b5d-fc3f-47d0-807f-6b93cb47f6bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_0e502aae-97b4-44f7-a52e-8ad7d1e89c84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_0e502aae-97b4-44f7-a52e-8ad7d1e89c84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_6e6c6975-566a-4bac-a2ac-d53092cf1762" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_6e6c6975-566a-4bac-a2ac-d53092cf1762" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_e5f4ae1b-1eda-4775-9cd3-8d124706dce6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_e5f4ae1b-1eda-4775-9cd3-8d124706dce6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_a6746cc7-c6be-46c4-932b-e612c7df51f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_a6746cc7-c6be-46c4-932b-e612c7df51f2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_e7de36bb-d06a-41a2-b6e5-e14447dc9fc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_e7de36bb-d06a-41a2-b6e5-e14447dc9fc4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_3e890b20-e3c6-429b-a126-9087a9cfc76f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_c75fdc02-18bd-4ce2-bbd2-c8cddebfecea" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_3e890b20-e3c6-429b-a126-9087a9cfc76f" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/INTANGIBLEASSETSANDGOODWILLScheduleofCarryingAmountofGoodwillDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#INTANGIBLEASSETSANDGOODWILLScheduleofCarryingAmountofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/INTANGIBLEASSETSANDGOODWILLScheduleofCarryingAmountofGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_dc405770-c2d7-4eeb-9a8b-a4c06b2ccec1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_e7e1fdcd-5c40-4d13-a2aa-6af1983f130d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_dc405770-c2d7-4eeb-9a8b-a4c06b2ccec1" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_e7e1fdcd-5c40-4d13-a2aa-6af1983f130d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_70790ebd-16a1-4954-8017-0cecbdcb3bc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_e7e1fdcd-5c40-4d13-a2aa-6af1983f130d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_70790ebd-16a1-4954-8017-0cecbdcb3bc4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_70790ebd-16a1-4954-8017-0cecbdcb3bc4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_70790ebd-16a1-4954-8017-0cecbdcb3bc4" xlink:to="loc_us-gaap_SegmentDomain_70790ebd-16a1-4954-8017-0cecbdcb3bc4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_d1ccba9a-e138-4a93-945f-d96962fb6735" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_70790ebd-16a1-4954-8017-0cecbdcb3bc4" xlink:to="loc_us-gaap_SegmentDomain_d1ccba9a-e138-4a93-945f-d96962fb6735" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_USAndCanadaSegmentMember_6480debf-712b-4fce-b2b2-9d0cd8b79c91" xlink:href="mar-20251231.xsd#mar_USAndCanadaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d1ccba9a-e138-4a93-945f-d96962fb6735" xlink:to="loc_mar_USAndCanadaSegmentMember_6480debf-712b-4fce-b2b2-9d0cd8b79c91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_EMEASegmentMember_2e720aeb-0955-4488-998e-40496413fa55" xlink:href="mar-20251231.xsd#mar_EMEASegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d1ccba9a-e138-4a93-945f-d96962fb6735" xlink:to="loc_mar_EMEASegmentMember_2e720aeb-0955-4488-998e-40496413fa55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_GreaterChinaMember_4a53b80a-bb43-4cc0-9dd5-2153d944d2fb" xlink:href="mar-20251231.xsd#mar_GreaterChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d1ccba9a-e138-4a93-945f-d96962fb6735" xlink:to="loc_mar_GreaterChinaMember_4a53b80a-bb43-4cc0-9dd5-2153d944d2fb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_APECMember_c19729d5-04a3-4c7f-a22a-64dc248ab27f" xlink:href="mar-20251231.xsd#mar_APECMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d1ccba9a-e138-4a93-945f-d96962fb6735" xlink:to="loc_mar_APECMember_c19729d5-04a3-4c7f-a22a-64dc248ab27f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_CaribbeanAndLatinAmericaSegmentMember_910a2726-154d-472f-88fc-e001e52c2f8e" xlink:href="mar-20251231.xsd#mar_CaribbeanAndLatinAmericaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d1ccba9a-e138-4a93-945f-d96962fb6735" xlink:to="loc_mar_CaribbeanAndLatinAmericaSegmentMember_910a2726-154d-472f-88fc-e001e52c2f8e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_8eb3efc9-17a1-44cd-b049-aae713c76674" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_dc405770-c2d7-4eeb-9a8b-a4c06b2ccec1" xlink:to="loc_us-gaap_GoodwillRollForward_8eb3efc9-17a1-44cd-b049-aae713c76674" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_9da650c3-737e-4ce6-990c-e863a5bc8105" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_8eb3efc9-17a1-44cd-b049-aae713c76674" xlink:to="loc_us-gaap_Goodwill_9da650c3-737e-4ce6-990c-e863a5bc8105" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_8ceab95a-b91f-4a85-8c4a-5ade43d34e05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_8eb3efc9-17a1-44cd-b049-aae713c76674" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_8ceab95a-b91f-4a85-8c4a-5ade43d34e05" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_5cb04396-384d-4abe-9ae5-a7a0c206e996" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/PROPERTYANDEQUIPMENTScheduleofCompositionofourPropertyandEquipmentBalancesDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#PROPERTYANDEQUIPMENTScheduleofCompositionofourPropertyandEquipmentBalancesDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/PROPERTYANDEQUIPMENTScheduleofCompositionofourPropertyandEquipmentBalancesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f5067505-5495-4a17-8253-947797fcf8fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_c29637b3-8043-47cd-8e9e-96f51188671b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f5067505-5495-4a17-8253-947797fcf8fc" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_c29637b3-8043-47cd-8e9e-96f51188671b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c66ff7d6-2503-4033-8136-ec7d7064c513" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_c29637b3-8043-47cd-8e9e-96f51188671b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c66ff7d6-2503-4033-8136-ec7d7064c513" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c66ff7d6-2503-4033-8136-ec7d7064c513_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c66ff7d6-2503-4033-8136-ec7d7064c513" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c66ff7d6-2503-4033-8136-ec7d7064c513_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_faf1e025-95b4-494c-a80b-ed79f21c6cd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c66ff7d6-2503-4033-8136-ec7d7064c513" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_faf1e025-95b4-494c-a80b-ed79f21c6cd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_9ae8ee5d-76d0-41c9-8e18-2e1f7ee26211" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_faf1e025-95b4-494c-a80b-ed79f21c6cd5" xlink:to="loc_us-gaap_LandMember_9ae8ee5d-76d0-41c9-8e18-2e1f7ee26211" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_BuildingAndLeaseholdImprovementsMember_df157202-5c37-4f81-bb6b-8a51780e008f" xlink:href="mar-20251231.xsd#mar_BuildingAndLeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_faf1e025-95b4-494c-a80b-ed79f21c6cd5" xlink:to="loc_mar_BuildingAndLeaseholdImprovementsMember_df157202-5c37-4f81-bb6b-8a51780e008f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_7331328a-f77c-441c-9d40-33630ca361a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_faf1e025-95b4-494c-a80b-ed79f21c6cd5" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_7331328a-f77c-441c-9d40-33630ca361a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_fdbc9100-1486-47d9-9268-69f9e7f62f84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_faf1e025-95b4-494c-a80b-ed79f21c6cd5" xlink:to="loc_us-gaap_ConstructionInProgressMember_fdbc9100-1486-47d9-9268-69f9e7f62f84" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_992061ce-ed95-479c-863b-46fb1b821ada" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f5067505-5495-4a17-8253-947797fcf8fc" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_992061ce-ed95-479c-863b-46fb1b821ada" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_c001c009-edb2-41cc-9fb0-59e365b9d3ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f5067505-5495-4a17-8253-947797fcf8fc" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_c001c009-edb2-41cc-9fb0-59e365b9d3ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_2830c58d-ec68-4a43-9562-e6532a0db85f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_f5067505-5495-4a17-8253-947797fcf8fc" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_2830c58d-ec68-4a43-9562-e6532a0db85f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/PROPERTYANDEQUIPMENTAdditionalInformationDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#PROPERTYANDEQUIPMENTAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/PROPERTYANDEQUIPMENTAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ce1a1c71-a929-46bc-bfeb-18e6cb993d1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ba6b32df-d329-47ec-9213-917a0b108bc5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ce1a1c71-a929-46bc-bfeb-18e6cb993d1f" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ba6b32df-d329-47ec-9213-917a0b108bc5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_8ad3c94f-4964-4e16-9e3c-986cade34351" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ba6b32df-d329-47ec-9213-917a0b108bc5" xlink:to="loc_srt_RangeAxis_8ad3c94f-4964-4e16-9e3c-986cade34351" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8ad3c94f-4964-4e16-9e3c-986cade34351_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_8ad3c94f-4964-4e16-9e3c-986cade34351" xlink:to="loc_srt_RangeMember_8ad3c94f-4964-4e16-9e3c-986cade34351_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ca4a1622-28dd-49be-8372-72708728d099" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_8ad3c94f-4964-4e16-9e3c-986cade34351" xlink:to="loc_srt_RangeMember_ca4a1622-28dd-49be-8372-72708728d099" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_2e1807fa-0cb6-4fb4-9f47-9569f2425cd2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ca4a1622-28dd-49be-8372-72708728d099" xlink:to="loc_srt_MinimumMember_2e1807fa-0cb6-4fb4-9f47-9569f2425cd2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_dd3c542b-2c4f-46e2-82c2-813e6bc94d32" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ca4a1622-28dd-49be-8372-72708728d099" xlink:to="loc_srt_MaximumMember_dd3c542b-2c4f-46e2-82c2-813e6bc94d32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_246d6933-a781-4fe9-b5a6-04e6ae1c77b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ba6b32df-d329-47ec-9213-917a0b108bc5" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_246d6933-a781-4fe9-b5a6-04e6ae1c77b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_246d6933-a781-4fe9-b5a6-04e6ae1c77b1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_246d6933-a781-4fe9-b5a6-04e6ae1c77b1" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_246d6933-a781-4fe9-b5a6-04e6ae1c77b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_69d7c184-432a-4ec4-9d91-9f93bbc5e5a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_246d6933-a781-4fe9-b5a6-04e6ae1c77b1" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_69d7c184-432a-4ec4-9d91-9f93bbc5e5a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ReimbursedCostsMember_6a59217f-69c3-4859-ac8f-34471ef61363" xlink:href="mar-20251231.xsd#mar_ReimbursedCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_69d7c184-432a-4ec4-9d91-9f93bbc5e5a8" xlink:to="loc_mar_ReimbursedCostsMember_6a59217f-69c3-4859-ac8f-34471ef61363" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_2cc633f9-a2f1-4e8c-9be9-0f786eb84eb0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ba6b32df-d329-47ec-9213-917a0b108bc5" xlink:to="loc_srt_StatementGeographicalAxis_2cc633f9-a2f1-4e8c-9be9-0f786eb84eb0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_2cc633f9-a2f1-4e8c-9be9-0f786eb84eb0_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_2cc633f9-a2f1-4e8c-9be9-0f786eb84eb0" xlink:to="loc_srt_SegmentGeographicalDomain_2cc633f9-a2f1-4e8c-9be9-0f786eb84eb0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_a0468321-5eba-4c25-91e9-e7762a09e1b1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_2cc633f9-a2f1-4e8c-9be9-0f786eb84eb0" xlink:to="loc_srt_SegmentGeographicalDomain_a0468321-5eba-4c25-91e9-e7762a09e1b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_dc7f9ae9-3b9f-4d19-a106-8f7bc6bb17db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_a0468321-5eba-4c25-91e9-e7762a09e1b1" xlink:to="loc_us-gaap_NonUsMember_dc7f9ae9-3b9f-4d19-a106-8f7bc6bb17db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_caccc72f-c463-4dec-814e-7716a3c6fe05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ce1a1c71-a929-46bc-bfeb-18e6cb993d1f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_caccc72f-c463-4dec-814e-7716a3c6fe05" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_33623cb3-ce72-4c8c-a180-1a537cd72521" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ce1a1c71-a929-46bc-bfeb-18e6cb993d1f" xlink:to="loc_us-gaap_Depreciation_33623cb3-ce72-4c8c-a180-1a537cd72521" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_e9f93a4d-e96b-4bed-97fc-00c19e91b101" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ce1a1c71-a929-46bc-bfeb-18e6cb993d1f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_e9f93a4d-e96b-4bed-97fc-00c19e91b101" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#FAIRVALUEOFFINANCIALINSTRUMENTSDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8908f45f-0cf5-4e56-ad87-57a95a7fca37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_d40eaec4-7855-4d83-ba80-57be0878ac68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8908f45f-0cf5-4e56-ad87-57a95a7fca37" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_d40eaec4-7855-4d83-ba80-57be0878ac68" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_543d167f-cbc9-4f3a-abee-9d00e4a7dd13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_d40eaec4-7855-4d83-ba80-57be0878ac68" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_543d167f-cbc9-4f3a-abee-9d00e4a7dd13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_543d167f-cbc9-4f3a-abee-9d00e4a7dd13_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_543d167f-cbc9-4f3a-abee-9d00e4a7dd13" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_543d167f-cbc9-4f3a-abee-9d00e4a7dd13_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_3644cd87-8ca2-43a5-890c-a29a6141d202" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_543d167f-cbc9-4f3a-abee-9d00e4a7dd13" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_3644cd87-8ca2-43a5-890c-a29a6141d202" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_2057d61b-023c-4f8b-a20f-6960a6b64cc7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_3644cd87-8ca2-43a5-890c-a29a6141d202" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_2057d61b-023c-4f8b-a20f-6960a6b64cc7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_a3001a10-370a-4138-acef-2ab8676548b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_2057d61b-023c-4f8b-a20f-6960a6b64cc7" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_a3001a10-370a-4138-acef-2ab8676548b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_8542f8ae-6b6f-434b-a98b-d3064c6ac7ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_2057d61b-023c-4f8b-a20f-6960a6b64cc7" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_8542f8ae-6b6f-434b-a98b-d3064c6ac7ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesAndLoansReceivableNetNoncurrent_001e21a6-e32d-438b-a99d-e347daa82ec4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesAndLoansReceivableNetNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8908f45f-0cf5-4e56-ad87-57a95a7fca37" xlink:to="loc_us-gaap_NotesAndLoansReceivableNetNoncurrent_001e21a6-e32d-438b-a99d-e347daa82ec4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_FinancialInstrumentsAssetsNoncurrent_798c96ad-84ec-45df-a2ee-363a1c11d15c" xlink:href="mar-20251231.xsd#mar_FinancialInstrumentsAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8908f45f-0cf5-4e56-ad87-57a95a7fca37" xlink:to="loc_mar_FinancialInstrumentsAssetsNoncurrent_798c96ad-84ec-45df-a2ee-363a1c11d15c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorLongTermNotes_d6f84b1a-456c-4438-a3bb-a57883a7ff91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorLongTermNotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8908f45f-0cf5-4e56-ad87-57a95a7fca37" xlink:to="loc_us-gaap_SeniorLongTermNotes_d6f84b1a-456c-4438-a3bb-a57883a7ff91" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperNoncurrent_baf4502b-b095-4ddb-a968-43cb8ffd3390" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialPaperNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8908f45f-0cf5-4e56-ad87-57a95a7fca37" xlink:to="loc_us-gaap_CommercialPaperNoncurrent_baf4502b-b095-4ddb-a968-43cb8ffd3390" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_FinancialInstrumentsLiabilitiesNoncurrent_ad2ab788-d302-4589-ae2b-39030327a07b" xlink:href="mar-20251231.xsd#mar_FinancialInstrumentsLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8908f45f-0cf5-4e56-ad87-57a95a7fca37" xlink:to="loc_mar_FinancialInstrumentsLiabilitiesNoncurrent_ad2ab788-d302-4589-ae2b-39030327a07b" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSScheduleofAccumulatedOtherComprehensiveIncomeActivityDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#ACCUMULATEDOTHERCOMPREHENSIVELOSSScheduleofAccumulatedOtherComprehensiveIncomeActivityDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSScheduleofAccumulatedOtherComprehensiveIncomeActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d9fb7020-73c4-4467-b581-04cad475ec70" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_5b6ee579-1ffb-452f-9824-77a494f2c11e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d9fb7020-73c4-4467-b581-04cad475ec70" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_5b6ee579-1ffb-452f-9824-77a494f2c11e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_e3eab090-4e25-4e32-982d-fdf98fc0305c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_5b6ee579-1ffb-452f-9824-77a494f2c11e" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_e3eab090-4e25-4e32-982d-fdf98fc0305c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e3eab090-4e25-4e32-982d-fdf98fc0305c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e3eab090-4e25-4e32-982d-fdf98fc0305c" xlink:to="loc_us-gaap_EquityComponentDomain_e3eab090-4e25-4e32-982d-fdf98fc0305c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a03d5e37-8aa2-4bb8-81fb-6ed811fcecde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e3eab090-4e25-4e32-982d-fdf98fc0305c" xlink:to="loc_us-gaap_EquityComponentDomain_a03d5e37-8aa2-4bb8-81fb-6ed811fcecde" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7c40629c-1fd5-4621-828b-117b22ef3037" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a03d5e37-8aa2-4bb8-81fb-6ed811fcecde" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7c40629c-1fd5-4621-828b-117b22ef3037" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_39087ad5-bd4e-45c1-bdd3-fcf98dca73ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7c40629c-1fd5-4621-828b-117b22ef3037" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_39087ad5-bd4e-45c1-bdd3-fcf98dca73ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_AccumulatedGainLossOtherAdjustmentsAttributableToParentMember_92644cc3-7d7c-436a-b1c5-b9cab481172f" xlink:href="mar-20251231.xsd#mar_AccumulatedGainLossOtherAdjustmentsAttributableToParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7c40629c-1fd5-4621-828b-117b22ef3037" xlink:to="loc_mar_AccumulatedGainLossOtherAdjustmentsAttributableToParentMember_92644cc3-7d7c-436a-b1c5-b9cab481172f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_19383408-0fc1-4490-b31d-c37ef8a5ba31" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d9fb7020-73c4-4467-b581-04cad475ec70" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_19383408-0fc1-4490-b31d-c37ef8a5ba31" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_bbd7d8fe-f903-416e-b324-7a8e260f95a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_19383408-0fc1-4490-b31d-c37ef8a5ba31" xlink:to="loc_us-gaap_StockholdersEquity_bbd7d8fe-f903-416e-b324-7a8e260f95a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_462dc008-d17c-49d5-9f99-e0cfaf1d2490" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_19383408-0fc1-4490-b31d-c37ef8a5ba31" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_462dc008-d17c-49d5-9f99-e0cfaf1d2490" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_922efbdc-23bc-4f76-8c0b-ef921599a685" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_OtherComprehensiveIncomeLossForeignCurrencyTranslationAndTranslationGainLossBeforeReclassificationAndTaxIntraEntityForeignCurrencyTransactionsLongTermInvestmentNature_47731ba3-1601-4cff-9438-0ba40517b542" xlink:href="mar-20251231.xsd#mar_OtherComprehensiveIncomeLossForeignCurrencyTranslationAndTranslationGainLossBeforeReclassificationAndTaxIntraEntityForeignCurrencyTransactionsLongTermInvestmentNature"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d9fb7020-73c4-4467-b581-04cad475ec70" xlink:to="loc_mar_OtherComprehensiveIncomeLossForeignCurrencyTranslationAndTranslationGainLossBeforeReclassificationAndTaxIntraEntityForeignCurrencyTransactionsLongTermInvestmentNature_47731ba3-1601-4cff-9438-0ba40517b542" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/BUSINESSSEGMENTSAdditionalInformationDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#BUSINESSSEGMENTSAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/BUSINESSSEGMENTSAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_1631315f-134e-46e2-a614-5d1137039b96" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_e915e999-423c-494b-9627-51cedff55bec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_1631315f-134e-46e2-a614-5d1137039b96" xlink:to="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_e915e999-423c-494b-9627-51cedff55bec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_ce769fda-85ff-486f-a04c-8dfbec4484c7" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_e915e999-423c-494b-9627-51cedff55bec" xlink:to="loc_srt_ConsolidationItemsAxis_ce769fda-85ff-486f-a04c-8dfbec4484c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_ce769fda-85ff-486f-a04c-8dfbec4484c7_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_ce769fda-85ff-486f-a04c-8dfbec4484c7" xlink:to="loc_srt_ConsolidationItemsDomain_ce769fda-85ff-486f-a04c-8dfbec4484c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_2693a28c-3d4b-46e1-9098-ffe621dbf27a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_ce769fda-85ff-486f-a04c-8dfbec4484c7" xlink:to="loc_srt_ConsolidationItemsDomain_2693a28c-3d4b-46e1-9098-ffe621dbf27a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_f66ef0fe-b68c-4952-b8c8-64acb07b135a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_2693a28c-3d4b-46e1-9098-ffe621dbf27a" xlink:to="loc_us-gaap_OperatingSegmentsMember_f66ef0fe-b68c-4952-b8c8-64acb07b135a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_76e9be5c-582c-4ed6-9b8c-a2ae4558c6ed" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_e915e999-423c-494b-9627-51cedff55bec" xlink:to="loc_srt_StatementGeographicalAxis_76e9be5c-582c-4ed6-9b8c-a2ae4558c6ed" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_76e9be5c-582c-4ed6-9b8c-a2ae4558c6ed_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_76e9be5c-582c-4ed6-9b8c-a2ae4558c6ed" xlink:to="loc_srt_SegmentGeographicalDomain_76e9be5c-582c-4ed6-9b8c-a2ae4558c6ed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_e6aa210d-3119-45a7-a493-4bbfcccc8179" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_76e9be5c-582c-4ed6-9b8c-a2ae4558c6ed" xlink:to="loc_srt_SegmentGeographicalDomain_e6aa210d-3119-45a7-a493-4bbfcccc8179" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_912707ba-e599-43e1-bade-f5aa89e650b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_e6aa210d-3119-45a7-a493-4bbfcccc8179" xlink:to="loc_us-gaap_NonUsMember_912707ba-e599-43e1-bade-f5aa89e650b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_c672554e-45dd-400c-b8d6-53b15cce5ef2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_e915e999-423c-494b-9627-51cedff55bec" xlink:to="loc_srt_ProductOrServiceAxis_c672554e-45dd-400c-b8d6-53b15cce5ef2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_c672554e-45dd-400c-b8d6-53b15cce5ef2_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_c672554e-45dd-400c-b8d6-53b15cce5ef2" xlink:to="loc_srt_ProductsAndServicesDomain_c672554e-45dd-400c-b8d6-53b15cce5ef2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_83965032-cd29-40f9-8bc1-b9234aa279b8" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_c672554e-45dd-400c-b8d6-53b15cce5ef2" xlink:to="loc_srt_ProductsAndServicesDomain_83965032-cd29-40f9-8bc1-b9234aa279b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ReimbursementsMember_d1ca0119-9744-4a87-8c1a-651a2f2c8548" xlink:href="mar-20251231.xsd#mar_ReimbursementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_83965032-cd29-40f9-8bc1-b9234aa279b8" xlink:to="loc_mar_ReimbursementsMember_d1ca0119-9744-4a87-8c1a-651a2f2c8548" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_d43c2c41-b9cb-4855-9949-8e679db36a16" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_1631315f-134e-46e2-a614-5d1137039b96" xlink:to="loc_us-gaap_NumberOfReportableSegments_d43c2c41-b9cb-4855-9949-8e679db36a16" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_e90f075b-b279-403f-b995-9e42cc8ce5e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_1631315f-134e-46e2-a614-5d1137039b96" xlink:to="loc_us-gaap_Revenues_e90f075b-b279-403f-b995-9e42cc8ce5e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_3e5eefad-7cc7-49a0-b729-1f14578de9b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_1631315f-134e-46e2-a614-5d1137039b96" xlink:to="loc_us-gaap_OperatingIncomeLoss_3e5eefad-7cc7-49a0-b729-1f14578de9b0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/BUSINESSSEGMENTSSummaryofSegmentRevenueSegmentExpensesandSegmentProfitsDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#BUSINESSSEGMENTSSummaryofSegmentRevenueSegmentExpensesandSegmentProfitsDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/BUSINESSSEGMENTSSummaryofSegmentRevenueSegmentExpensesandSegmentProfitsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_ab298cb2-2f0a-476a-a555-25c3ff1fec7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_ab298cb2-2f0a-476a-a555-25c3ff1fec7c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_0c7ae929-92e2-46f1-9d55-156c4bda0768" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_ab298cb2-2f0a-476a-a555-25c3ff1fec7c" xlink:to="loc_srt_ConsolidationItemsAxis_0c7ae929-92e2-46f1-9d55-156c4bda0768" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_0c7ae929-92e2-46f1-9d55-156c4bda0768_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_0c7ae929-92e2-46f1-9d55-156c4bda0768" xlink:to="loc_srt_ConsolidationItemsDomain_0c7ae929-92e2-46f1-9d55-156c4bda0768_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_4943437f-947b-4a17-a60e-8d2e22b1e05b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_0c7ae929-92e2-46f1-9d55-156c4bda0768" xlink:to="loc_srt_ConsolidationItemsDomain_4943437f-947b-4a17-a60e-8d2e22b1e05b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_341f9e60-625f-4d0a-a1f1-699aca95c5aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_4943437f-947b-4a17-a60e-8d2e22b1e05b" xlink:to="loc_us-gaap_OperatingSegmentsMember_341f9e60-625f-4d0a-a1f1-699aca95c5aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_deb27046-ea33-44c8-b4fd-7d8a516b7a8d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_ab298cb2-2f0a-476a-a555-25c3ff1fec7c" xlink:to="loc_srt_ProductOrServiceAxis_deb27046-ea33-44c8-b4fd-7d8a516b7a8d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_deb27046-ea33-44c8-b4fd-7d8a516b7a8d_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_deb27046-ea33-44c8-b4fd-7d8a516b7a8d" xlink:to="loc_srt_ProductsAndServicesDomain_deb27046-ea33-44c8-b4fd-7d8a516b7a8d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_27779e3f-b6af-4172-889c-4b215c703ace" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_deb27046-ea33-44c8-b4fd-7d8a516b7a8d" xlink:to="loc_srt_ProductsAndServicesDomain_27779e3f-b6af-4172-889c-4b215c703ace" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_FeeServiceMember_2fd4a27e-d8d3-4474-9c5d-94c2e4e41587" xlink:href="mar-20251231.xsd#mar_FeeServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_27779e3f-b6af-4172-889c-4b215c703ace" xlink:to="loc_mar_FeeServiceMember_2fd4a27e-d8d3-4474-9c5d-94c2e4e41587" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_OwnedLeasedandOtherMember_04e7c739-78d3-45f6-a807-8ff21a8596cb" xlink:href="mar-20251231.xsd#mar_OwnedLeasedandOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_27779e3f-b6af-4172-889c-4b215c703ace" xlink:to="loc_mar_OwnedLeasedandOtherMember_04e7c739-78d3-45f6-a807-8ff21a8596cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ReimbursementsMember_7ac4d15d-215e-407f-b7b9-90ef51ce0ae8" xlink:href="mar-20251231.xsd#mar_ReimbursementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_27779e3f-b6af-4172-889c-4b215c703ace" xlink:to="loc_mar_ReimbursementsMember_7ac4d15d-215e-407f-b7b9-90ef51ce0ae8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_b4f10010-3142-4840-9bdf-79dc7f25639e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_ab298cb2-2f0a-476a-a555-25c3ff1fec7c" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_b4f10010-3142-4840-9bdf-79dc7f25639e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_b4f10010-3142-4840-9bdf-79dc7f25639e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b4f10010-3142-4840-9bdf-79dc7f25639e" xlink:to="loc_us-gaap_SegmentDomain_b4f10010-3142-4840-9bdf-79dc7f25639e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_360e9ebe-4292-4884-baa6-33f76dda4a19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b4f10010-3142-4840-9bdf-79dc7f25639e" xlink:to="loc_us-gaap_SegmentDomain_360e9ebe-4292-4884-baa6-33f76dda4a19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_USAndCanadaSegmentMember_9d442998-b372-4d8a-96c1-6dde731620cb" xlink:href="mar-20251231.xsd#mar_USAndCanadaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_360e9ebe-4292-4884-baa6-33f76dda4a19" xlink:to="loc_mar_USAndCanadaSegmentMember_9d442998-b372-4d8a-96c1-6dde731620cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_EMEASegmentMember_628f8ae9-63de-4708-a56a-0a017c2329df" xlink:href="mar-20251231.xsd#mar_EMEASegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_360e9ebe-4292-4884-baa6-33f76dda4a19" xlink:to="loc_mar_EMEASegmentMember_628f8ae9-63de-4708-a56a-0a017c2329df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_GreaterChinaMember_40ee0495-0e5e-44e5-a33d-10cc834ac6df" xlink:href="mar-20251231.xsd#mar_GreaterChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_360e9ebe-4292-4884-baa6-33f76dda4a19" xlink:to="loc_mar_GreaterChinaMember_40ee0495-0e5e-44e5-a33d-10cc834ac6df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_APECMember_bcf0c214-e193-45e7-920c-d78bde66dd3a" xlink:href="mar-20251231.xsd#mar_APECMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_360e9ebe-4292-4884-baa6-33f76dda4a19" xlink:to="loc_mar_APECMember_bcf0c214-e193-45e7-920c-d78bde66dd3a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_RevenuesGrossOfCapitalizedContractCostAmortization_a0f94ac6-8be0-4e60-8e47-627e1c7d40ef" xlink:href="mar-20251231.xsd#mar_RevenuesGrossOfCapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_mar_RevenuesGrossOfCapitalizedContractCostAmortization_a0f94ac6-8be0-4e60-8e47-627e1c7d40ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAmortization_a9a2607b-82a5-40f4-ad55-d73d522d025d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_us-gaap_CapitalizedContractCostAmortization_a9a2607b-82a5-40f4-ad55-d73d522d025d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_61127e68-5296-41b2-ab18-c8b27d9bdfed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_us-gaap_Revenues_61127e68-5296-41b2-ab18-c8b27d9bdfed" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_7688a61d-b577-4101-8cbc-1b97b138b955" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_us-gaap_CostOfRevenue_7688a61d-b577-4101-8cbc-1b97b138b955" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_DepreciationAmortizationAndOtherExcludingCapitalizedContractCostAmortization_bb770a5d-b0f9-48a0-aede-9f8ae567b632" xlink:href="mar-20251231.xsd#mar_DepreciationAmortizationAndOtherExcludingCapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_mar_DepreciationAmortizationAndOtherExcludingCapitalizedContractCostAmortization_bb770a5d-b0f9-48a0-aede-9f8ae567b632" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_894b0967-7136-4856-a8b3-2e5e30590855" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_894b0967-7136-4856-a8b3-2e5e30590855" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_067b093f-94f6-4959-8c6b-e33fab0387db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_067b093f-94f6-4959-8c6b-e33fab0387db" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_c7eaee62-412a-43d5-b7b5-49e265ab676d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_d9e66d70-424c-44fa-b89e-43e6336e9701" xlink:to="loc_us-gaap_OperatingIncomeLoss_c7eaee62-412a-43d5-b7b5-49e265ab676d" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/BUSINESSSEGMENTSScheduleofReconciliationofTotalSegmentRevenueandProfittoConsolidatedRevenueandProfitDetails" xlink:type="simple" xlink:href="mar-20251231.xsd#BUSINESSSEGMENTSScheduleofReconciliationofTotalSegmentRevenueandProfittoConsolidatedRevenueandProfitDetails"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/BUSINESSSEGMENTSScheduleofReconciliationofTotalSegmentRevenueandProfittoConsolidatedRevenueandProfitDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_b42fc9e3-9a9b-4cd1-a440-59862ce6cb80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_7710271b-d926-41c1-8255-d9c1574d9010" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_b42fc9e3-9a9b-4cd1-a440-59862ce6cb80" xlink:to="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_7710271b-d926-41c1-8255-d9c1574d9010" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_e869f7ba-8476-40aa-b72b-41eecbb16a39" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_7710271b-d926-41c1-8255-d9c1574d9010" xlink:to="loc_srt_ConsolidationItemsAxis_e869f7ba-8476-40aa-b72b-41eecbb16a39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_e869f7ba-8476-40aa-b72b-41eecbb16a39_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_e869f7ba-8476-40aa-b72b-41eecbb16a39" xlink:to="loc_srt_ConsolidationItemsDomain_e869f7ba-8476-40aa-b72b-41eecbb16a39_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_244f04c9-d2f4-48e2-b973-c11676210453" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_e869f7ba-8476-40aa-b72b-41eecbb16a39" xlink:to="loc_srt_ConsolidationItemsDomain_244f04c9-d2f4-48e2-b973-c11676210453" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_627fcb4a-1347-4e1d-bad5-a8d3ab5eba79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_244f04c9-d2f4-48e2-b973-c11676210453" xlink:to="loc_us-gaap_OperatingSegmentsMember_627fcb4a-1347-4e1d-bad5-a8d3ab5eba79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_017174f9-6942-4724-8f9a-b0e927c16ceb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_244f04c9-d2f4-48e2-b973-c11676210453" xlink:to="loc_us-gaap_CorporateNonSegmentMember_017174f9-6942-4724-8f9a-b0e927c16ceb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_bbd9f936-fc6c-4b7f-aa92-911ab03b22a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_b42fc9e3-9a9b-4cd1-a440-59862ce6cb80" xlink:to="loc_us-gaap_Revenues_bbd9f936-fc6c-4b7f-aa92-911ab03b22a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_IncomeLossBeforeInterestExpenseAndTaxes_29b9ccf5-75ba-4bf1-b687-180ec22f4074" xlink:href="mar-20251231.xsd#mar_IncomeLossBeforeInterestExpenseAndTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_b42fc9e3-9a9b-4cd1-a440-59862ce6cb80" xlink:to="loc_mar_IncomeLossBeforeInterestExpenseAndTaxes_29b9ccf5-75ba-4bf1-b687-180ec22f4074" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_5aa030bc-d6a7-48e4-be73-88a0866191ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_b42fc9e3-9a9b-4cd1-a440-59862ce6cb80" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_5aa030bc-d6a7-48e4-be73-88a0866191ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_e75c08c7-5129-4af7-84cc-2f884b976ae5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_b42fc9e3-9a9b-4cd1-a440-59862ce6cb80" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_e75c08c7-5129-4af7-84cc-2f884b976ae5" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.marriott.com/role/RELATEDPARTYTRANSACTIONSScheduleofFinancialDataResultingfromTransactionswithRelatedPartiesIncomeStatementDataDetail" xlink:type="simple" xlink:href="mar-20251231.xsd#RELATEDPARTYTRANSACTIONSScheduleofFinancialDataResultingfromTransactionswithRelatedPartiesIncomeStatementDataDetail"/>
  <link:definitionLink xlink:role="http://www.marriott.com/role/RELATEDPARTYTRANSACTIONSScheduleofFinancialDataResultingfromTransactionswithRelatedPartiesIncomeStatementDataDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_377ce32a-edfc-469d-999c-355c50ef304d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_f33c7a6a-acf1-46d7-8e1b-dd0e718c2349" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_377ce32a-edfc-469d-999c-355c50ef304d" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_f33c7a6a-acf1-46d7-8e1b-dd0e718c2349" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_3ae38175-2ab0-4ad6-afbf-463aee837647" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_f33c7a6a-acf1-46d7-8e1b-dd0e718c2349" xlink:to="loc_srt_ProductOrServiceAxis_3ae38175-2ab0-4ad6-afbf-463aee837647" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_3ae38175-2ab0-4ad6-afbf-463aee837647_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_3ae38175-2ab0-4ad6-afbf-463aee837647" xlink:to="loc_srt_ProductsAndServicesDomain_3ae38175-2ab0-4ad6-afbf-463aee837647_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_1614ddc5-e858-451e-a01c-2268a728e3df" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_3ae38175-2ab0-4ad6-afbf-463aee837647" xlink:to="loc_srt_ProductsAndServicesDomain_1614ddc5-e858-451e-a01c-2268a728e3df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_mar_ReimbursementsMember_51e8a3ff-6845-4bca-9262-134356901391" xlink:href="mar-20251231.xsd#mar_ReimbursementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_1614ddc5-e858-451e-a01c-2268a728e3df" xlink:to="loc_mar_ReimbursementsMember_51e8a3ff-6845-4bca-9262-134356901391" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_8a018b8c-93c5-44e7-89a7-ab05caab16f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_f33c7a6a-acf1-46d7-8e1b-dd0e718c2349" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_8a018b8c-93c5-44e7-89a7-ab05caab16f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_8a018b8c-93c5-44e7-89a7-ab05caab16f6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_8a018b8c-93c5-44e7-89a7-ab05caab16f6" xlink:to="loc_us-gaap_RelatedPartyDomain_8a018b8c-93c5-44e7-89a7-ab05caab16f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_e5b284fe-491a-4cff-b4a7-621d94adb6ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_8a018b8c-93c5-44e7-89a7-ab05caab16f6" xlink:to="loc_us-gaap_RelatedPartyDomain_e5b284fe-491a-4cff-b4a7-621d94adb6ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvesteeMember_9b7902b9-4722-41e1-a547-e9e5216171cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvesteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_e5b284fe-491a-4cff-b4a7-621d94adb6ad" xlink:to="loc_us-gaap_EquityMethodInvesteeMember_9b7902b9-4722-41e1-a547-e9e5216171cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_27b0cbcd-54a9-4a7f-a49e-e6f0161268a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_377ce32a-edfc-469d-999c-355c50ef304d" xlink:to="loc_us-gaap_Revenues_27b0cbcd-54a9-4a7f-a49e-e6f0161268a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_b1e3d420-3057-4ca9-b6cf-b36f13034ad1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_377ce32a-edfc-469d-999c-355c50ef304d" xlink:to="loc_us-gaap_CostOfRevenue_b1e3d420-3057-4ca9-b6cf-b36f13034ad1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_6425b53c-b4f9-4ee6-8397-5808cbb24750" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_377ce32a-edfc-469d-999c-355c50ef304d" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_6425b53c-b4f9-4ee6-8397-5808cbb24750" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:type="arc" order="41"/>
  </link:definitionLink>
</link:linkbase>
