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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019ff773-d7d2-7c0b-8d59-c33160a99a9b,g:59831d02-f16b-4e34-ba2f-b523fff1e101-->
<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.reynoldsgroupholdings.com/role/CondensedConsolidatedStatementsofIncome" xlink:type="simple" xlink:href="reyn-20260930.xsd#CondensedConsolidatedStatementsofIncome"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/CondensedConsolidatedStatementsofIncome" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019ff773-d88d-7bce-8437-ced945f4182a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_StatementTable_019ff773-d88d-7bce-8437-ced945f4182a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-75f4-8609-321b675db99a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ff773-d88d-7bce-8437-ced945f4182a" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-75f4-8609-321b675db99a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-75f4-8609-321b675db99a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-75f4-8609-321b675db99a" xlink:to="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-75f4-8609-321b675db99a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-7ef3-b165-24e9f62cfb4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-75f4-8609-321b675db99a" xlink:to="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-7ef3-b165-24e9f62cfb4d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_019ff773-d88d-79df-8b19-97924c51c3d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-7ef3-b165-24e9f62cfb4d" xlink:to="loc_us-gaap_NonrelatedPartyMember_019ff773-d88d-79df-8b19-97924c51c3d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019ff773-d88d-787a-94fa-fbfb53669845" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-7ef3-b165-24e9f62cfb4d" xlink:to="loc_us-gaap_RelatedPartyMember_019ff773-d88d-787a-94fa-fbfb53669845" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff773-d88d-781b-820e-1add07287955" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff773-d88d-781b-820e-1add07287955" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019ff773-d88d-7c9c-95bd-add01644aacd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019ff773-d88d-7c9c-95bd-add01644aacd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019ff773-d88d-70a6-abac-82cc7a576bd1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_GrossProfit_019ff773-d88d-70a6-abac-82cc7a576bd1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019ff773-d88d-7a6e-b4e9-464ce02d23b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019ff773-d88d-7a6e-b4e9-464ce02d23b8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingIncomeExpenseNet_019ff773-d88d-7a3e-a82c-6fe1ebc9b1b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherOperatingIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_OtherOperatingIncomeExpenseNet_019ff773-d88d-7a3e-a82c-6fe1ebc9b1b9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperations_019ff773-d88d-7af8-b240-94610f042212" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperations_019ff773-d88d-7af8-b240-94610f042212" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019ff773-d88d-7d68-bce1-d446959716de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019ff773-d88d-7d68-bce1-d446959716de" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_GainLossOnDebtModification_019ff773-d88d-79ae-850a-f460326bb6d6" xlink:href="reyn-20260930.xsd#reyn_GainLossOnDebtModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_reyn_GainLossOnDebtModification_019ff773-d88d-79ae-850a-f460326bb6d6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ff773-d88d-7d87-8c24-44f5ebd6fd10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ff773-d88d-7d87-8c24-44f5ebd6fd10" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019ff773-d88d-7f1e-ad59-f0ce23a80f39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019ff773-d88d-7f1e-ad59-f0ce23a80f39" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ff773-d88d-7e49-8283-a0471fb31e03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_NetIncomeLoss_019ff773-d88d-7e49-8283-a0471fb31e03" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_019ff773-d88d-7cde-892b-4f0f3887985c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_EarningsPerShareAbstract_019ff773-d88d-7cde-892b-4f0f3887985c" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019ff773-d88d-7b2a-b3a7-005ad4df27f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019ff773-d88d-7cde-892b-4f0f3887985c" xlink:to="loc_us-gaap_EarningsPerShareBasic_019ff773-d88d-7b2a-b3a7-005ad4df27f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019ff773-d88d-7988-a91d-446f5bd42345" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019ff773-d88d-7cde-892b-4f0f3887985c" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019ff773-d88d-7988-a91d-446f5bd42345" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019ff773-d88d-7696-888b-eef1c0f2cdf2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-76b9-9c77-a04bc78381ec" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019ff773-d88d-7696-888b-eef1c0f2cdf2" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019ff773-d88d-7f86-870a-bea6d8e5c510" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019ff773-d88d-7696-888b-eef1c0f2cdf2" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019ff773-d88d-7f86-870a-bea6d8e5c510" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019ff773-d88d-7304-a499-4525a3d01cd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019ff773-d88d-7696-888b-eef1c0f2cdf2" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019ff773-d88d-7304-a499-4525a3d01cd7" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/CondensedConsolidatedStatementsofStockholdersEquity" xlink:type="simple" xlink:href="reyn-20260930.xsd#CondensedConsolidatedStatementsofStockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/CondensedConsolidatedStatementsofStockholdersEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ff773-d88d-7d88-8d0c-09dee3c0b61d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019ff773-d88d-7f9b-8507-8d0652a24465" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-7d88-8d0c-09dee3c0b61d" xlink:to="loc_us-gaap_StatementTable_019ff773-d88d-7f9b-8507-8d0652a24465" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7b37-8668-2596bce90289" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ff773-d88d-7f9b-8507-8d0652a24465" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7b37-8668-2596bce90289" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7b37-8668-2596bce90289_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7b37-8668-2596bce90289" xlink:to="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7b37-8668-2596bce90289_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7107-a552-f7f48ad514a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7b37-8668-2596bce90289" xlink:to="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7107-a552-f7f48ad514a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019ff773-d88d-7b12-aba0-8ec90c2731fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7107-a552-f7f48ad514a2" xlink:to="loc_us-gaap_CommonStockMember_019ff773-d88d-7b12-aba0-8ec90c2731fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019ff773-d88d-7a61-aa9d-f601c2444ae5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7107-a552-f7f48ad514a2" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019ff773-d88d-7a61-aa9d-f601c2444ae5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019ff773-d88d-75d6-bb31-a9e1c3638882" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7107-a552-f7f48ad514a2" xlink:to="loc_us-gaap_RetainedEarningsMember_019ff773-d88d-75d6-bb31-a9e1c3638882" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff773-d88d-7f4a-8fe1-fbc4e0babdd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7107-a552-f7f48ad514a2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff773-d88d-7f4a-8fe1-fbc4e0babdd7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff773-d88d-7a33-83b0-b3c0b608e55c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff773-d88d-7d88-8d0c-09dee3c0b61d" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff773-d88d-7a33-83b0-b3c0b608e55c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff773-d88d-7d55-9043-643506b7ff95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff773-d88d-7a33-83b0-b3c0b608e55c" xlink:to="loc_us-gaap_StockholdersEquity_019ff773-d88d-7d55-9043-643506b7ff95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ff773-d88d-7aa0-975b-56fb09a9d9ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff773-d88d-7a33-83b0-b3c0b608e55c" xlink:to="loc_us-gaap_NetIncomeLoss_019ff773-d88d-7aa0-975b-56fb09a9d9ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ff773-d88d-7f63-88a3-8723008a8490" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff773-d88d-7a33-83b0-b3c0b608e55c" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ff773-d88d-7f63-88a3-8723008a8490" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_019ff773-d88d-73f8-b75f-bfbb2433fcd0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff773-d88d-7a33-83b0-b3c0b608e55c" xlink:to="loc_us-gaap_DividendsCommonStockCash_019ff773-d88d-73f8-b75f-bfbb2433fcd0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_019ff773-d88d-7527-a169-c9fff5c7888b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff773-d88d-7a33-83b0-b3c0b608e55c" xlink:to="loc_us-gaap_StockholdersEquityOther_019ff773-d88d-7527-a169-c9fff5c7888b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff773-d88d-76a1-b016-ec736bd24511" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/DescriptionofBusinessandBasisofPresentationDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#DescriptionofBusinessandBasisofPresentationDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/DescriptionofBusinessandBasisofPresentationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramTable_019ff773-d88d-7f63-bcfa-72d8c3f6fd05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:to="loc_us-gaap_SupplierFinanceProgramTable_019ff773-d88d-7f63-bcfa-72d8c3f6fd05" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramAxis_019ff773-d88d-7c19-bfbd-2912c82e75ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SupplierFinanceProgramTable_019ff773-d88d-7f63-bcfa-72d8c3f6fd05" xlink:to="loc_us-gaap_SupplierFinanceProgramAxis_019ff773-d88d-7c19-bfbd-2912c82e75ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramDomain_019ff773-d88d-7c19-bfbd-2912c82e75ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SupplierFinanceProgramAxis_019ff773-d88d-7c19-bfbd-2912c82e75ce" xlink:to="loc_us-gaap_SupplierFinanceProgramDomain_019ff773-d88d-7c19-bfbd-2912c82e75ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramDomain_019ff773-d88d-7168-84a7-73a73333e977" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SupplierFinanceProgramAxis_019ff773-d88d-7c19-bfbd-2912c82e75ce" xlink:to="loc_us-gaap_SupplierFinanceProgramDomain_019ff773-d88d-7168-84a7-73a73333e977" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_SCFBankMember_019ff773-d88d-7bba-9b13-22a8d2d1dfa2" xlink:href="reyn-20260930.xsd#reyn_SCFBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramDomain_019ff773-d88d-7168-84a7-73a73333e977" xlink:to="loc_reyn_SCFBankMember_019ff773-d88d-7bba-9b13-22a8d2d1dfa2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_019ff773-d88d-7e18-a8a3-6228fb501003" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SupplierFinanceProgramTable_019ff773-d88d-7f63-bcfa-72d8c3f6fd05" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_019ff773-d88d-7e18-a8a3-6228fb501003" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019ff773-d88d-7e18-a8a3-6228fb501003_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019ff773-d88d-7e18-a8a3-6228fb501003" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019ff773-d88d-7e18-a8a3-6228fb501003_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019ff773-d88d-78ab-a219-174791bcb58e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019ff773-d88d-7e18-a8a3-6228fb501003" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019ff773-d88d-78ab-a219-174791bcb58e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_JPMorganChaseBankMemberMember_019ff773-d88d-793c-999c-80364c004d08" xlink:href="reyn-20260930.xsd#reyn_JPMorganChaseBankMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_019ff773-d88d-78ab-a219-174791bcb58e" xlink:to="loc_reyn_JPMorganChaseBankMemberMember_019ff773-d88d-793c-999c-80364c004d08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019ff773-d88d-79cd-9656-19ac71cdb9ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:to="loc_us-gaap_NumberOfReportableSegments_019ff773-d88d-79cd-9656-19ac71cdb9ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_019ff773-d88d-7ebc-80d3-f126db63d04a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_019ff773-d88d-7ebc-80d3-f126db63d04a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_019ff773-d88d-7f59-b15c-3835288de324" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_019ff773-d88d-7f59-b15c-3835288de324" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramObligation_019ff773-d88d-7792-8af8-402d17454ba7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:to="loc_us-gaap_SupplierFinanceProgramObligation_019ff773-d88d-7792-8af8-402d17454ba7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_AccountsReceivablesSoldForFactoring_019ff773-d88d-70a0-b56d-ba8764b09541" xlink:href="reyn-20260930.xsd#reyn_AccountsReceivablesSoldForFactoring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:to="loc_reyn_AccountsReceivablesSoldForFactoring_019ff773-d88d-70a0-b56d-ba8764b09541" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_AccountsReceivableFactored_019ff773-d88d-7616-862e-09c5cf1f8be4" xlink:href="reyn-20260930.xsd#reyn_AccountsReceivableFactored"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramLineItems_019ff773-d88d-77fd-a4d2-749a9f329713" xlink:to="loc_reyn_AccountsReceivableFactored_019ff773-d88d-7616-862e-09c5cf1f8be4" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/DebtScheduleofLongtermDebtDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#DebtScheduleofLongtermDebtDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/DebtScheduleofLongtermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7772-85d1-3fe90f2af2e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7504-8599-093f0de57032" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7772-85d1-3fe90f2af2e7" xlink:to="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7504-8599-093f0de57032" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7a8f-9aee-97c06c19dc5b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7504-8599-093f0de57032" xlink:to="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7a8f-9aee-97c06c19dc5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7a8f-9aee-97c06c19dc5b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7a8f-9aee-97c06c19dc5b" xlink:to="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7a8f-9aee-97c06c19dc5b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7802-a6dc-7f279c6e716a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7a8f-9aee-97c06c19dc5b" xlink:to="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7802-a6dc-7f279c6e716a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_TermLoanFacilityMember_019ff773-d88d-7e1c-809e-5bb70b329844" xlink:href="reyn-20260930.xsd#reyn_TermLoanFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7802-a6dc-7f279c6e716a" xlink:to="loc_reyn_TermLoanFacilityMember_019ff773-d88d-7e1c-809e-5bb70b329844" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019ff773-d88d-7838-b5b5-848215f4d708" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7772-85d1-3fe90f2af2e7" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019ff773-d88d-7838-b5b5-848215f4d708" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019ff773-d88d-7214-bf84-3f843224474a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7772-85d1-3fe90f2af2e7" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019ff773-d88d-7214-bf84-3f843224474a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019ff773-d88d-79c6-84eb-72a023be3058" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7772-85d1-3fe90f2af2e7" xlink:to="loc_us-gaap_LongTermDebt_019ff773-d88d-79c6-84eb-72a023be3058" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019ff773-d88d-76f4-8d5a-a9313b8fd66a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7772-85d1-3fe90f2af2e7" xlink:to="loc_us-gaap_LongTermDebtCurrent_019ff773-d88d-76f4-8d5a-a9313b8fd66a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019ff773-d88d-770e-82dc-449299889e61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7772-85d1-3fe90f2af2e7" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019ff773-d88d-770e-82dc-449299889e61" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/DebtAdditionalInformationDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#DebtAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/DebtAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7003-ad25-74ceb8785beb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7003-ad25-74ceb8785beb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019ff773-d88d-7b0e-aac6-f2f31e8d5fba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7003-ad25-74ceb8785beb" xlink:to="loc_us-gaap_DebtInstrumentAxis_019ff773-d88d-7b0e-aac6-f2f31e8d5fba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019ff773-d88d-7b0e-aac6-f2f31e8d5fba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019ff773-d88d-7b0e-aac6-f2f31e8d5fba" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019ff773-d88d-7b0e-aac6-f2f31e8d5fba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019ff773-d88d-7f9a-b9b3-30452d0f99d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019ff773-d88d-7b0e-aac6-f2f31e8d5fba" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019ff773-d88d-7f9a-b9b3-30452d0f99d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_ExternalDebtFacilitiesMember_019ff773-d88d-7901-ad15-db755750bb2c" xlink:href="reyn-20260930.xsd#reyn_ExternalDebtFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019ff773-d88d-7f9a-b9b3-30452d0f99d8" xlink:to="loc_reyn_ExternalDebtFacilitiesMember_019ff773-d88d-7901-ad15-db755750bb2c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7b3a-8841-e0873c220d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7003-ad25-74ceb8785beb" xlink:to="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7b3a-8841-e0873c220d7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7b3a-8841-e0873c220d7a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7b3a-8841-e0873c220d7a" xlink:to="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7b3a-8841-e0873c220d7a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7a1c-a78c-c60902f8cb78" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019ff773-d88d-7b3a-8841-e0873c220d7a" xlink:to="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7a1c-a78c-c60902f8cb78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019ff773-d88d-7c57-8a99-257d91dbb6e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7a1c-a78c-c60902f8cb78" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019ff773-d88d-7c57-8a99-257d91dbb6e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_NewSeniorSecuredTermLoanFacilityMember_019ff773-d88d-73b8-87f9-751d8bf271d4" xlink:href="reyn-20260930.xsd#reyn_NewSeniorSecuredTermLoanFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7a1c-a78c-c60902f8cb78" xlink:to="loc_reyn_NewSeniorSecuredTermLoanFacilityMember_019ff773-d88d-73b8-87f9-751d8bf271d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_TermLoanFacilityMember_019ff773-d88d-726e-b235-dc16bd3dba52" xlink:href="reyn-20260930.xsd#reyn_TermLoanFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019ff773-d88d-7a1c-a78c-c60902f8cb78" xlink:to="loc_reyn_TermLoanFacilityMember_019ff773-d88d-726e-b235-dc16bd3dba52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019ff773-d88d-7ea2-bce6-52e00abd606b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019ff773-d88d-7003-ad25-74ceb8785beb" xlink:to="loc_us-gaap_VariableRateAxis_019ff773-d88d-7ea2-bce6-52e00abd606b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019ff773-d88d-7ea2-bce6-52e00abd606b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019ff773-d88d-7ea2-bce6-52e00abd606b" xlink:to="loc_us-gaap_VariableRateDomain_019ff773-d88d-7ea2-bce6-52e00abd606b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019ff773-d88d-7ba5-9cfe-d152427bca2e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019ff773-d88d-7ea2-bce6-52e00abd606b" xlink:to="loc_us-gaap_VariableRateDomain_019ff773-d88d-7ba5-9cfe-d152427bca2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_019ff773-d88d-71dc-a19c-284ecb49e1b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019ff773-d88d-7ba5-9cfe-d152427bca2e" xlink:to="loc_us-gaap_BaseRateMember_019ff773-d88d-71dc-a19c-284ecb49e1b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019ff773-d88d-75fc-882b-47825ee48761" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredOvernightFinancingRateSofrMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019ff773-d88d-7ba5-9cfe-d152427bca2e" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019ff773-d88d-75fc-882b-47825ee48761" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019ff773-d88d-77ce-8a49-7d0e95654589" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019ff773-d88d-77ce-8a49-7d0e95654589" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_GainLossOnDebtModification_019ff773-d88d-7cdc-828d-deb80798206d" xlink:href="reyn-20260930.xsd#reyn_GainLossOnDebtModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_reyn_GainLossOnDebtModification_019ff773-d88d-7cdc-828d-deb80798206d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_019ff773-d88d-7b9b-8327-2516b37e6b27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_019ff773-d88d-7b9b-8327-2516b37e6b27" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_019ff773-d88d-7ad6-a4fe-25b374a9a0af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_019ff773-d88d-7ad6-a4fe-25b374a9a0af" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsGross_019ff773-d88d-7231-96eb-1ec56268334d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtIssuanceCostsLineOfCreditArrangementsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsGross_019ff773-d88d-7231-96eb-1ec56268334d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019ff773-d88d-7570-8d22-7ded72cfa939" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019ff773-d88d-7570-8d22-7ded72cfa939" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019ff773-d88d-7fe9-a5c2-a2cc519bf124" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019ff773-d88d-7fe9-a5c2-a2cc519bf124" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_QuarterlyUnreimbursedLettersOfCreditMinimumPercentage_019ff773-d88d-7c8d-9917-ebb46bb40e92" xlink:href="reyn-20260930.xsd#reyn_QuarterlyUnreimbursedLettersOfCreditMinimumPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_reyn_QuarterlyUnreimbursedLettersOfCreditMinimumPercentage_019ff773-d88d-7c8d-9917-ebb46bb40e92" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPayment_019ff773-d88d-7b7d-81f5-60e8c84cf9c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentPeriodicPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPayment_019ff773-d88d-7b7d-81f5-60e8c84cf9c1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_019ff773-d88d-7b7b-bd56-ad3eae34c430" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_019ff773-d88d-7b7b-bd56-ad3eae34c430" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019ff773-d88d-7228-9015-3e52cbac3c2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_LineOfCredit_019ff773-d88d-7228-9015-3e52cbac3c2d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019ff773-d88d-7cba-ba9f-b25c695a7b61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ff773-d88d-7ab6-8f49-01b39a77554e" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019ff773-d88d-7cba-ba9f-b25c695a7b61" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/FinancialInstrumentsAdditionalInformationDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#FinancialInstrumentsAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/FinancialInstrumentsAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7c17-82bd-357dc8d14a10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7211-bb25-9aeb5d1f30d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7c17-82bd-357dc8d14a10" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7211-bb25-9aeb5d1f30d6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7680-ace8-918c35945e3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7211-bb25-9aeb5d1f30d6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7680-ace8-918c35945e3a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7680-ace8-918c35945e3a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7680-ace8-918c35945e3a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7680-ace8-918c35945e3a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7108-a193-8d943fed6a35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7680-ace8-918c35945e3a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7108-a193-8d943fed6a35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019ff773-d88d-7bfc-9619-16d2d9f6e8ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7108-a193-8d943fed6a35" xlink:to="loc_us-gaap_InterestRateSwapMember_019ff773-d88d-7bfc-9619-16d2d9f6e8ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7361-a734-71d0748e0b9b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7211-bb25-9aeb5d1f30d6" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7361-a734-71d0748e0b9b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-7361-a734-71d0748e0b9b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7361-a734-71d0748e0b9b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-7361-a734-71d0748e0b9b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-78a3-b300-a6cd4f3cf109" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7361-a734-71d0748e0b9b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-78a3-b300-a6cd4f3cf109" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019ff773-d88d-788e-a73b-8d78716734b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-78a3-b300-a6cd4f3cf109" xlink:to="loc_us-gaap_CashFlowHedgingMember_019ff773-d88d-788e-a73b-8d78716734b5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019ff773-d88d-7e53-bd78-f4fae973c51b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7211-bb25-9aeb5d1f30d6" xlink:to="loc_srt_RangeAxis_019ff773-d88d-7e53-bd78-f4fae973c51b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ff773-d88d-7e53-bd78-f4fae973c51b_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019ff773-d88d-7e53-bd78-f4fae973c51b" xlink:to="loc_srt_RangeMember_019ff773-d88d-7e53-bd78-f4fae973c51b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ff773-d88d-7263-a0d7-7e66cf264350" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019ff773-d88d-7e53-bd78-f4fae973c51b" xlink:to="loc_srt_RangeMember_019ff773-d88d-7263-a0d7-7e66cf264350" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019ff773-d88d-7ba0-8609-1342dbbd68b0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019ff773-d88d-7263-a0d7-7e66cf264350" xlink:to="loc_srt_MinimumMember_019ff773-d88d-7ba0-8609-1342dbbd68b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019ff773-d88d-7c27-9c14-f6b9e49cd2a4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019ff773-d88d-7263-a0d7-7e66cf264350" xlink:to="loc_srt_MaximumMember_019ff773-d88d-7c27-9c14-f6b9e49cd2a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_019ff773-d88d-752c-9dd7-56deeaa13ed9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019ff773-d88d-7263-a0d7-7e66cf264350" xlink:to="loc_srt_WeightedAverageMember_019ff773-d88d-752c-9dd7-56deeaa13ed9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019ff773-d88d-7132-8d91-5d5b2d3d8562" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7c17-82bd-357dc8d14a10" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019ff773-d88d-7132-8d91-5d5b2d3d8562" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeVariableInterestRate_019ff773-d88d-7edd-a796-df66f2a1612b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeVariableInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7c17-82bd-357dc8d14a10" xlink:to="loc_us-gaap_DerivativeVariableInterestRate_019ff773-d88d-7edd-a796-df66f2a1612b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_DerivativeEffectiveWeightedAverageInterestRate_019ff773-d88d-79a1-b368-9f4c4a26ac57" xlink:href="reyn-20260930.xsd#reyn_DerivativeEffectiveWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7c17-82bd-357dc8d14a10" xlink:to="loc_reyn_DerivativeEffectiveWeightedAverageInterestRate_019ff773-d88d-79a1-b368-9f4c4a26ac57" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/FinancialInstrumentsScheduleofDerivativebyBalanceSheetGroupingDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#FinancialInstrumentsScheduleofDerivativebyBalanceSheetGroupingDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/FinancialInstrumentsScheduleofDerivativebyBalanceSheetGroupingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7be2-92c2-25aff5dc0d97" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7130-901c-04e207c72a1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7be2-92c2-25aff5dc0d97" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7130-901c-04e207c72a1f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7433-b053-d58e5b7d1aa0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7130-901c-04e207c72a1f" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7433-b053-d58e5b7d1aa0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7433-b053-d58e5b7d1aa0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7433-b053-d58e5b7d1aa0" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7433-b053-d58e5b7d1aa0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7bb7-ab5f-afe77ce452a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019ff773-d88d-7433-b053-d58e5b7d1aa0" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7bb7-ab5f-afe77ce452a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019ff773-d88d-757a-bdb5-ed480a1c9f96" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ff773-d88d-7bb7-ab5f-afe77ce452a3" xlink:to="loc_us-gaap_InterestRateSwapMember_019ff773-d88d-757a-bdb5-ed480a1c9f96" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7bff-b744-278afe968d12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019ff773-d88d-7130-901c-04e207c72a1f" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7bff-b744-278afe968d12" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-7bff-b744-278afe968d12_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7bff-b744-278afe968d12" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-7bff-b744-278afe968d12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-7f79-84ce-acb8195c05b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019ff773-d88d-7bff-b744-278afe968d12" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-7f79-84ce-acb8195c05b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019ff773-d88d-7ee7-8e1c-9693217a99d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019ff773-d88d-7f79-84ce-acb8195c05b0" xlink:to="loc_us-gaap_CashFlowHedgingMember_019ff773-d88d-7ee7-8e1c-9693217a99d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019ff773-d88d-7a63-9a89-e228215a9697" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7be2-92c2-25aff5dc0d97" xlink:to="loc_us-gaap_AssetsAbstract_019ff773-d88d-7a63-9a89-e228215a9697" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsCurrent_019ff773-d88d-7212-aaa5-0feb7b70c850" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ff773-d88d-7a63-9a89-e228215a9697" xlink:to="loc_us-gaap_DerivativeAssetsCurrent_019ff773-d88d-7212-aaa5-0feb7b70c850" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsNoncurrent_019ff773-d88d-7847-b412-98d0b5ca2426" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ff773-d88d-7a63-9a89-e228215a9697" xlink:to="loc_us-gaap_DerivativeAssetsNoncurrent_019ff773-d88d-7847-b412-98d0b5ca2426" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019ff773-d88d-7bd0-883e-273b2181035b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ff773-d88d-7a63-9a89-e228215a9697" xlink:to="loc_us-gaap_DerivativeAssets_019ff773-d88d-7bd0-883e-273b2181035b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_019ff773-d88d-7b6b-8c3f-efcaa8cc5629" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019ff773-d88d-7be2-92c2-25aff5dc0d97" xlink:to="loc_us-gaap_LiabilitiesAbstract_019ff773-d88d-7b6b-8c3f-efcaa8cc5629" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilitiesNoncurrent_019ff773-d88d-7cc8-b2d5-df252bf75f1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019ff773-d88d-7b6b-8c3f-efcaa8cc5629" xlink:to="loc_us-gaap_DerivativeLiabilitiesNoncurrent_019ff773-d88d-7cc8-b2d5-df252bf75f1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019ff773-d88d-76f6-aadd-b8c4c692eabf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019ff773-d88d-7b6b-8c3f-efcaa8cc5629" xlink:to="loc_us-gaap_DerivativeLiabilities_019ff773-d88d-76f6-aadd-b8c4c692eabf" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/StockbasedCompensationDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#StockbasedCompensationDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/StockbasedCompensationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff773-d88d-7e80-825c-c5aab1b23cd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff773-d88d-7f39-a508-aa99cd30ad1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff773-d88d-7e80-825c-c5aab1b23cd7" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff773-d88d-7f39-a508-aa99cd30ad1c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ff773-d88d-7105-8fdf-1bd1ee651b9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff773-d88d-7f39-a508-aa99cd30ad1c" xlink:to="loc_us-gaap_AwardTypeAxis_019ff773-d88d-7105-8fdf-1bd1ee651b9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff773-d88d-7105-8fdf-1bd1ee651b9e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019ff773-d88d-7105-8fdf-1bd1ee651b9e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff773-d88d-7105-8fdf-1bd1ee651b9e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff773-d88d-7bd1-9ea3-79f944c53603" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019ff773-d88d-7105-8fdf-1bd1ee651b9e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff773-d88d-7bd1-9ea3-79f944c53603" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff773-d88d-7986-a294-0ee0edcb9ba1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff773-d88d-7bd1-9ea3-79f944c53603" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff773-d88d-7986-a294-0ee0edcb9ba1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019ff773-d88d-768b-8bdf-b4496995c3e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff773-d88d-7bd1-9ea3-79f944c53603" xlink:to="loc_us-gaap_PerformanceSharesMember_019ff773-d88d-768b-8bdf-b4496995c3e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019ff773-d88d-7932-bf59-4a930ddcdbd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff773-d88d-7e80-825c-c5aab1b23cd7" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019ff773-d88d-7932-bf59-4a930ddcdbd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019ff773-d88d-764e-abf4-ffdc395171f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff773-d88d-7e80-825c-c5aab1b23cd7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019ff773-d88d-764e-abf4-ffdc395171f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ff773-d88d-734b-8f98-3a819e66aed6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff773-d88d-7e80-825c-c5aab1b23cd7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ff773-d88d-734b-8f98-3a819e66aed6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff773-d88d-7d4f-93e0-ea340963018c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff773-d88d-7e80-825c-c5aab1b23cd7" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff773-d88d-7d4f-93e0-ea340963018c" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#AccumulatedOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019ff773-d88d-746c-9b89-9fdfb94f1ee8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019ff773-d88d-7821-9f93-dccc8810bdb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019ff773-d88d-746c-9b89-9fdfb94f1ee8" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019ff773-d88d-7821-9f93-dccc8810bdb8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7e61-92f0-adf3b1352498" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019ff773-d88d-7821-9f93-dccc8810bdb8" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7e61-92f0-adf3b1352498" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7e61-92f0-adf3b1352498_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7e61-92f0-adf3b1352498" xlink:to="loc_us-gaap_EquityComponentDomain_019ff773-d88d-7e61-92f0-adf3b1352498_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ff773-d88d-73b8-a86c-773767135ede" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019ff773-d88d-7e61-92f0-adf3b1352498" xlink:to="loc_us-gaap_EquityComponentDomain_019ff773-d88d-73b8-a86c-773767135ede" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff773-d88d-721e-9ce1-2ee1d70414b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff773-d88d-73b8-a86c-773767135ede" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff773-d88d-721e-9ce1-2ee1d70414b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019ff773-d88d-7639-af22-793aaa7db6a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff773-d88d-721e-9ce1-2ee1d70414b0" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019ff773-d88d-7639-af22-793aaa7db6a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019ff773-d88d-7ed0-860b-1624bd318802" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff773-d88d-721e-9ce1-2ee1d70414b0" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019ff773-d88d-7ed0-860b-1624bd318802" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019ff773-d88d-7fc9-b657-468189d806b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff773-d88d-721e-9ce1-2ee1d70414b0" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019ff773-d88d-7fc9-b657-468189d806b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ff773-d88d-729d-ad77-239c5ebd2029" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019ff773-d88d-746c-9b89-9fdfb94f1ee8" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ff773-d88d-729d-ad77-239c5ebd2029" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff773-d88d-7848-93ba-c6c1ada6de4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ff773-d88d-729d-ad77-239c5ebd2029" xlink:to="loc_us-gaap_StockholdersEquity_019ff773-d88d-7848-93ba-c6c1ada6de4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_019ff773-d88d-7919-b848-b91510a8de8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ff773-d88d-729d-ad77-239c5ebd2029" xlink:to="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_019ff773-d88d-7919-b848-b91510a8de8a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_019ff773-d88d-7893-984c-bdc19d5e44e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ff773-d88d-729d-ad77-239c5ebd2029" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_019ff773-d88d-7893-984c-bdc19d5e44e5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_019ff773-d88d-7003-bbca-de9fed567f2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAociCurrentPeriodTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ff773-d88d-729d-ad77-239c5ebd2029" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_019ff773-d88d-7003-bbca-de9fed567f2a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff773-d88d-7c34-a198-554f74e636d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/SegmentInformationAdditionalInformationDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#SegmentInformationAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/SegmentInformationAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7782-ae7f-4007910f6e0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-7144-8b4f-f0c0afd1e049" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7782-ae7f-4007910f6e0e" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-7144-8b4f-f0c0afd1e049" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7375-875e-585f308c616f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-7144-8b4f-f0c0afd1e049" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7375-875e-585f308c616f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff773-d88d-7375-875e-585f308c616f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7375-875e-585f308c616f" xlink:to="loc_us-gaap_SegmentDomain_019ff773-d88d-7375-875e-585f308c616f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff773-d88d-7fa1-b235-36708a955c1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7375-875e-585f308c616f" xlink:to="loc_us-gaap_SegmentDomain_019ff773-d88d-7fa1-b235-36708a955c1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_ReynoldsCookingAndKitchenEssentialsMember_019ff773-d88d-763a-83e9-61a5ce8c8a2b" xlink:href="reyn-20260930.xsd#reyn_ReynoldsCookingAndKitchenEssentialsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7fa1-b235-36708a955c1b" xlink:to="loc_reyn_ReynoldsCookingAndKitchenEssentialsMember_019ff773-d88d-763a-83e9-61a5ce8c8a2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyWasteAndCleanupMember_019ff773-d88d-7ea3-8475-f595f55d2fbb" xlink:href="reyn-20260930.xsd#reyn_HeftyWasteAndCleanupMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7fa1-b235-36708a955c1b" xlink:to="loc_reyn_HeftyWasteAndCleanupMember_019ff773-d88d-7ea3-8475-f595f55d2fbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyHomeAndTablewareMember_019ff773-d88d-7765-90fa-94d9c295e5ae" xlink:href="reyn-20260930.xsd#reyn_HeftyHomeAndTablewareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7fa1-b235-36708a955c1b" xlink:to="loc_reyn_HeftyHomeAndTablewareMember_019ff773-d88d-7765-90fa-94d9c295e5ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyStorageAndOrganizationMember_019ff773-d88d-77bd-92bb-9a022a03c18a" xlink:href="reyn-20260930.xsd#reyn_HeftyStorageAndOrganizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7fa1-b235-36708a955c1b" xlink:to="loc_reyn_HeftyStorageAndOrganizationMember_019ff773-d88d-77bd-92bb-9a022a03c18a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019ff773-d88d-7cd9-82d3-ee3d78b4829f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7782-ae7f-4007910f6e0e" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019ff773-d88d-7cd9-82d3-ee3d78b4829f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ff773-d88d-71d1-9dfc-accbc2268174" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7782-ae7f-4007910f6e0e" xlink:to="loc_us-gaap_Goodwill_019ff773-d88d-71d1-9dfc-accbc2268174" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019ff773-d88d-76d9-8c5b-f305ba778e8f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7782-ae7f-4007910f6e0e" xlink:to="loc_us-gaap_NumberOfReportableSegments_019ff773-d88d-76d9-8c5b-f305ba778e8f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/SegmentInformationScheduleofAdjustedEBITDADetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#SegmentInformationScheduleofAdjustedEBITDADetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/SegmentInformationScheduleofAdjustedEBITDADetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7e7b-a97d-eab3e63616e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-7b65-916d-dc609d5859d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7e7b-a97d-eab3e63616e3" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-7b65-916d-dc609d5859d8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7e90-abc1-1dc6c2ef771e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-7b65-916d-dc609d5859d8" xlink:to="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7e90-abc1-1dc6c2ef771e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7e90-abc1-1dc6c2ef771e_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7e90-abc1-1dc6c2ef771e" xlink:to="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7e90-abc1-1dc6c2ef771e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7632-ad4d-89164c551818" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7e90-abc1-1dc6c2ef771e" xlink:to="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7632-ad4d-89164c551818" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ff773-d88d-7c01-a2c7-54bb3dae3077" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7632-ad4d-89164c551818" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ff773-d88d-7c01-a2c7-54bb3dae3077" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019ff773-d88d-78d0-87dd-af77fb6ea1bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7632-ad4d-89164c551818" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019ff773-d88d-78d0-87dd-af77fb6ea1bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7ce5-81bd-bc343dfc8bac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-7b65-916d-dc609d5859d8" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7ce5-81bd-bc343dfc8bac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff773-d88d-7ce5-81bd-bc343dfc8bac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7ce5-81bd-bc343dfc8bac" xlink:to="loc_us-gaap_SegmentDomain_019ff773-d88d-7ce5-81bd-bc343dfc8bac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff773-d88d-7b3d-b99c-c05e697a07e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-7ce5-81bd-bc343dfc8bac" xlink:to="loc_us-gaap_SegmentDomain_019ff773-d88d-7b3d-b99c-c05e697a07e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_ReynoldsCookingAndKitchenEssentialsMember_019ff773-d88d-7f59-82ae-44f6e3a02781" xlink:href="reyn-20260930.xsd#reyn_ReynoldsCookingAndKitchenEssentialsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7b3d-b99c-c05e697a07e5" xlink:to="loc_reyn_ReynoldsCookingAndKitchenEssentialsMember_019ff773-d88d-7f59-82ae-44f6e3a02781" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyWasteAndCleanupMember_019ff773-d88d-7395-b095-f69e81b9a836" xlink:href="reyn-20260930.xsd#reyn_HeftyWasteAndCleanupMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7b3d-b99c-c05e697a07e5" xlink:to="loc_reyn_HeftyWasteAndCleanupMember_019ff773-d88d-7395-b095-f69e81b9a836" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyHomeAndTablewareMember_019ff773-d88d-7fb1-9180-4de9bdecd12f" xlink:href="reyn-20260930.xsd#reyn_HeftyHomeAndTablewareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7b3d-b99c-c05e697a07e5" xlink:to="loc_reyn_HeftyHomeAndTablewareMember_019ff773-d88d-7fb1-9180-4de9bdecd12f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyStorageAndOrganizationMember_019ff773-d88d-7ef6-82e9-f82a75871dd7" xlink:href="reyn-20260930.xsd#reyn_HeftyStorageAndOrganizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7b3d-b99c-c05e697a07e5" xlink:to="loc_reyn_HeftyStorageAndOrganizationMember_019ff773-d88d-7ef6-82e9-f82a75871dd7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff773-d88d-7b56-a75e-34d7df5d2c0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7e7b-a97d-eab3e63616e3" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff773-d88d-7b56-a75e-34d7df5d2c0c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019ff773-d88d-78f5-8fe1-1010d1d598af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7e7b-a97d-eab3e63616e3" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019ff773-d88d-78f5-8fe1-1010d1d598af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_AdjustedEBITDAFromContinuingOperations_019ff773-d88d-7c46-9e39-eedac104f806" xlink:href="reyn-20260930.xsd#reyn_AdjustedEBITDAFromContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7e7b-a97d-eab3e63616e3" xlink:to="loc_reyn_AdjustedEBITDAFromContinuingOperations_019ff773-d88d-7c46-9e39-eedac104f806" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019ff773-d88d-7ca7-990e-2f99b6bab5bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7e7b-a97d-eab3e63616e3" xlink:to="loc_us-gaap_DepreciationAndAmortization_019ff773-d88d-7ca7-990e-2f99b6bab5bd" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/SegmentInformationScheduleofSegmentAssetsDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#SegmentInformationScheduleofSegmentAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/SegmentInformationScheduleofSegmentAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7a40-8e40-8f671d849875" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-723c-a2b9-c2702fa8c84b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7a40-8e40-8f671d849875" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-723c-a2b9-c2702fa8c84b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ff773-d88d-77b6-8493-9c7caecdd6bb" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-723c-a2b9-c2702fa8c84b" xlink:to="loc_srt_ConsolidationItemsAxis_019ff773-d88d-77b6-8493-9c7caecdd6bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ff773-d88d-77b6-8493-9c7caecdd6bb_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019ff773-d88d-77b6-8493-9c7caecdd6bb" xlink:to="loc_srt_ConsolidationItemsDomain_019ff773-d88d-77b6-8493-9c7caecdd6bb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ff773-d88d-75dc-8172-4e368ff1e083" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019ff773-d88d-77b6-8493-9c7caecdd6bb" xlink:to="loc_srt_ConsolidationItemsDomain_019ff773-d88d-75dc-8172-4e368ff1e083" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ff773-d88d-7ff5-91df-d10f8983e432" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ff773-d88d-75dc-8172-4e368ff1e083" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ff773-d88d-7ff5-91df-d10f8983e432" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019ff773-d88d-7cd2-b7d8-a0bff888d8f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ff773-d88d-75dc-8172-4e368ff1e083" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019ff773-d88d-7cd2-b7d8-a0bff888d8f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-712b-8ddb-9d79906bc46f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-723c-a2b9-c2702fa8c84b" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-712b-8ddb-9d79906bc46f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff773-d88d-712b-8ddb-9d79906bc46f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-712b-8ddb-9d79906bc46f" xlink:to="loc_us-gaap_SegmentDomain_019ff773-d88d-712b-8ddb-9d79906bc46f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff773-d88d-7bcb-9194-f48dc5c181c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff773-d88d-712b-8ddb-9d79906bc46f" xlink:to="loc_us-gaap_SegmentDomain_019ff773-d88d-7bcb-9194-f48dc5c181c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_ReynoldsCookingAndKitchenEssentialsMember_019ff773-d88d-7028-821d-79c3811c8361" xlink:href="reyn-20260930.xsd#reyn_ReynoldsCookingAndKitchenEssentialsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7bcb-9194-f48dc5c181c8" xlink:to="loc_reyn_ReynoldsCookingAndKitchenEssentialsMember_019ff773-d88d-7028-821d-79c3811c8361" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyWasteAndCleanupMember_019ff773-d88d-7835-abb9-1c41454288d9" xlink:href="reyn-20260930.xsd#reyn_HeftyWasteAndCleanupMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7bcb-9194-f48dc5c181c8" xlink:to="loc_reyn_HeftyWasteAndCleanupMember_019ff773-d88d-7835-abb9-1c41454288d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyHomeAndTablewareMember_019ff773-d88d-7327-afeb-448d80455155" xlink:href="reyn-20260930.xsd#reyn_HeftyHomeAndTablewareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7bcb-9194-f48dc5c181c8" xlink:to="loc_reyn_HeftyHomeAndTablewareMember_019ff773-d88d-7327-afeb-448d80455155" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_HeftyStorageAndOrganizationMember_019ff773-d88d-7e7d-a3a1-64b285be8099" xlink:href="reyn-20260930.xsd#reyn_HeftyStorageAndOrganizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff773-d88d-7bcb-9194-f48dc5c181c8" xlink:to="loc_reyn_HeftyStorageAndOrganizationMember_019ff773-d88d-7e7d-a3a1-64b285be8099" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019ff773-d88d-7503-bdc4-aa11a84421bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7a40-8e40-8f671d849875" xlink:to="loc_us-gaap_Assets_019ff773-d88d-7503-bdc4-aa11a84421bb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/SegmentInformationScheduleofReconciliationofTotalSegmentAdjustedEBITDAtoGAAPIncomeBeforeIncomeTaxesDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#SegmentInformationScheduleofReconciliationofTotalSegmentAdjustedEBITDAtoGAAPIncomeBeforeIncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/SegmentInformationScheduleofReconciliationofTotalSegmentAdjustedEBITDAtoGAAPIncomeBeforeIncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7d45-a477-bd03b97e8e0b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-79ac-9cc8-da9d45267ef1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7d45-a477-bd03b97e8e0b" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-79ac-9cc8-da9d45267ef1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7144-b156-3f0ebf050b2c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ff773-d88d-79ac-9cc8-da9d45267ef1" xlink:to="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7144-b156-3f0ebf050b2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7144-b156-3f0ebf050b2c_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7144-b156-3f0ebf050b2c" xlink:to="loc_srt_ConsolidationItemsDomain_019ff773-d88d-7144-b156-3f0ebf050b2c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ff773-d88d-74ba-b287-bb81ea562029" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019ff773-d88d-7144-b156-3f0ebf050b2c" xlink:to="loc_srt_ConsolidationItemsDomain_019ff773-d88d-74ba-b287-bb81ea562029" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ff773-d88d-7db4-acc6-f06bc96a3ce7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ff773-d88d-74ba-b287-bb81ea562029" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ff773-d88d-7db4-acc6-f06bc96a3ce7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019ff773-d88d-71cd-8a24-a00c175e2692" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ff773-d88d-74ba-b287-bb81ea562029" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019ff773-d88d-71cd-8a24-a00c175e2692" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_AdjustedEBITDAFromContinuingOperations_019ff773-d88d-7f1e-9e69-e1bfe1922857" xlink:href="reyn-20260930.xsd#reyn_AdjustedEBITDAFromContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7d45-a477-bd03b97e8e0b" xlink:to="loc_reyn_AdjustedEBITDAFromContinuingOperations_019ff773-d88d-7f1e-9e69-e1bfe1922857" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ff773-d88d-7d45-a477-bd03b97e8e0b" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019ff773-d88d-7792-901c-86d6493752aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_us-gaap_DepreciationAndAmortization_019ff773-d88d-7792-901c-86d6493752aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019ff773-d88d-714e-9b22-1fb9e9287a5f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019ff773-d88d-714e-9b22-1fb9e9287a5f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses_01a15d87-6d99-78ca-b5af-b7fad9bbb2f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses_01a15d87-6d99-78ca-b5af-b7fad9bbb2f4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_GainLossOnDebtModification_019ff773-d88d-7866-a9c4-c982b01c4198" xlink:href="reyn-20260930.xsd#reyn_GainLossOnDebtModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_reyn_GainLossOnDebtModification_019ff773-d88d-7866-a9c4-c982b01c4198" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_CostToExecuteStrategicInitiatives_019ff773-d88d-72af-8aac-4b06ada3d9dd" xlink:href="reyn-20260930.xsd#reyn_CostToExecuteStrategicInitiatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_reyn_CostToExecuteStrategicInitiatives_019ff773-d88d-72af-8aac-4b06ada3d9dd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_CEOTransitionCosts_019ff773-d88d-76ba-ae92-21c1d10fdf53" xlink:href="reyn-20260930.xsd#reyn_CEOTransitionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_reyn_CEOTransitionCosts_019ff773-d88d-76ba-ae92-21c1d10fdf53" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_01a1778e-9b97-7af8-8146-0d3530d1e299" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_01a1778e-9b97-7af8-8146-0d3530d1e299" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ff773-d88d-776b-9bc3-fc79bda31d52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterestAbstract_019ff773-d88d-7676-8b67-e2106a02c107" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ff773-d88d-776b-9bc3-fc79bda31d52" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/RelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#RelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019ff773-d88d-7fb3-8e84-1ab371bd0b29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019ff773-d88d-7d84-a4a8-8dbf97f60fd8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019ff773-d88d-7fb3-8e84-1ab371bd0b29" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019ff773-d88d-7d84-a4a8-8dbf97f60fd8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-7914-82c1-42944363cac7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019ff773-d88d-7d84-a4a8-8dbf97f60fd8" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-7914-82c1-42944363cac7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-7914-82c1-42944363cac7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-7914-82c1-42944363cac7" xlink:to="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-7914-82c1-42944363cac7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-700b-825a-28e5c1a0ca10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ff773-d88d-7914-82c1-42944363cac7" xlink:to="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-700b-825a-28e5c1a0ca10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_PEIGroupMember_019ff773-d88d-7cca-8180-ac3d55436a15" xlink:href="reyn-20260930.xsd#reyn_PEIGroupMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-700b-825a-28e5c1a0ca10" xlink:to="loc_reyn_PEIGroupMember_019ff773-d88d-7cca-8180-ac3d55436a15" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_PackagingFinanceLimitedMember_019ff773-d88d-706c-811b-71724b1d698d" xlink:href="reyn-20260930.xsd#reyn_PackagingFinanceLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019ff773-d88d-700b-825a-28e5c1a0ca10" xlink:to="loc_reyn_PackagingFinanceLimitedMember_019ff773-d88d-706c-811b-71724b1d698d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019ff773-d88d-7d88-99d4-592f24d3e96d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019ff773-d88d-7d84-a4a8-8dbf97f60fd8" xlink:to="loc_srt_ProductOrServiceAxis_019ff773-d88d-7d88-99d4-592f24d3e96d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ff773-d88d-7d88-99d4-592f24d3e96d_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019ff773-d88d-7d88-99d4-592f24d3e96d" xlink:to="loc_srt_ProductsAndServicesDomain_019ff773-d88d-7d88-99d4-592f24d3e96d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ff773-d88d-7ec9-999e-04b9445deced" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019ff773-d88d-7d88-99d4-592f24d3e96d" xlink:to="loc_srt_ProductsAndServicesDomain_019ff773-d88d-7ec9-999e-04b9445deced" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CargoAndFreightMember_019ff773-d88d-7115-8c23-7b57b67fe152" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CargoAndFreightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ff773-d88d-7ec9-999e-04b9445deced" xlink:to="loc_us-gaap_CargoAndFreightMember_019ff773-d88d-7115-8c23-7b57b67fe152" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff773-d88d-7a8f-a774-46c086e2f80f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019ff773-d88d-7fb3-8e84-1ab371bd0b29" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff773-d88d-7a8f-a774-46c086e2f80f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_019ff773-d88d-70fb-9963-16238b60e14a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019ff773-d88d-7fb3-8e84-1ab371bd0b29" xlink:to="loc_us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty_019ff773-d88d-70fb-9963-16238b60e14a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019ff773-d88d-74ec-af97-1289ad2f1935" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019ff773-d88d-7fb3-8e84-1ab371bd0b29" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019ff773-d88d-74ec-af97-1289ad2f1935" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_019ff773-d88d-75b4-a3cd-255bb892e311" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019ff773-d88d-7fb3-8e84-1ab371bd0b29" xlink:to="loc_us-gaap_PaymentsOfDividends_019ff773-d88d-75b4-a3cd-255bb892e311" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.reynoldsgroupholdings.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="reyn-20260930.xsd#SubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://www.reynoldsgroupholdings.com/role/SubsequentEventsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019ff773-d88d-715f-ba6a-c9b01e485818" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019ff773-d88d-785b-835f-315e0b9a0155" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff773-d88d-715f-ba6a-c9b01e485818" xlink:to="loc_us-gaap_SubsequentEventTable_019ff773-d88d-785b-835f-315e0b9a0155" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_01a13907-845e-79ce-8d05-9bbcc62a633b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019ff773-d88d-785b-835f-315e0b9a0155" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_01a13907-845e-79ce-8d05-9bbcc62a633b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a13907-845e-79ce-8d05-9bbcc62a633b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_01a13907-845e-79ce-8d05-9bbcc62a633b" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a13907-845e-79ce-8d05-9bbcc62a633b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a13907-845e-7048-bc51-86dbb04d15a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_01a13907-845e-79ce-8d05-9bbcc62a633b" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a13907-845e-7048-bc51-86dbb04d15a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_reyn_OwlsHeadAlloysMember_01a13907-845e-7d95-90d9-5f99ac13147f" xlink:href="reyn-20260930.xsd#reyn_OwlsHeadAlloysMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a13907-845e-7048-bc51-86dbb04d15a4" xlink:to="loc_reyn_OwlsHeadAlloysMember_01a13907-845e-7d95-90d9-5f99ac13147f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019ff773-d88d-78f0-b1d1-569f4c9a7042" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019ff773-d88d-785b-835f-315e0b9a0155" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019ff773-d88d-78f0-b1d1-569f4c9a7042" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019ff773-d88d-78f0-b1d1-569f4c9a7042_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019ff773-d88d-78f0-b1d1-569f4c9a7042" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019ff773-d88d-78f0-b1d1-569f4c9a7042_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019ff773-d88d-7852-b2d8-6f0399dd9651" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019ff773-d88d-78f0-b1d1-569f4c9a7042" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019ff773-d88d-7852-b2d8-6f0399dd9651" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019ff773-d88d-7e1f-b07d-6f0ccfba8498" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019ff773-d88d-7852-b2d8-6f0399dd9651" xlink:to="loc_us-gaap_SubsequentEventMember_019ff773-d88d-7e1f-b07d-6f0ccfba8498" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_01a13907-845e-71eb-b457-310402bb6117" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff773-d88d-715f-ba6a-c9b01e485818" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_01a13907-845e-71eb-b457-310402bb6117" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019ff773-d88d-7413-9358-5bdc897ffbf0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff773-d88d-715f-ba6a-c9b01e485818" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019ff773-d88d-7413-9358-5bdc897ffbf0" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
