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

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2021 Workiva-->
<!--r:fd9b0e3b-6f96-439b-ad18-6f171e06efa2,g:32818867-1fa1-4af6-ac39-e69f23024ce6-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:ptlo="http://portillos.com/20210926" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://portillos.com/20210926">
  <xs:import namespace="http://fasb.org/srt/2021-01-31" schemaLocation="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2021-01-31" schemaLocation="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd"/>
  <xs:import namespace="http://www.w3.org/1999/xlink" schemaLocation="http://www.xbrl.org/2003/xlink-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd"/>
  <xs:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei/2021" schemaLocation="https://xbrl.sec.gov/dei/2021/dei-2021.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ptlo-20210926_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ptlo-20210926_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ptlo-20210926_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ptlo-20210926_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="COVERPAGE" roleURI="http://portillos.com/role/COVERPAGE">
        <link:definition>0001001 - Document - COVER PAGE</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDBALANCESHEETSUNAUDITED" roleURI="http://portillos.com/role/CONDENSEDBALANCESHEETSUNAUDITED">
        <link:definition>1001002 - Statement - CONDENSED BALANCE SHEETS (UNAUDITED)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDBALANCESHEETSUNAUDITEDParenthetical" roleURI="http://portillos.com/role/CONDENSEDBALANCESHEETSUNAUDITEDParenthetical">
        <link:definition>1002003 - Statement - CONDENSED BALANCE SHEETS (UNAUDITED) (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDBALANCESHEETSUNAUDITED" roleURI="http://portillos.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUNAUDITED">
        <link:definition>1003004 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDBALANCESHEETSUNAUDITEDParenthetical" roleURI="http://portillos.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUNAUDITEDParenthetical">
        <link:definition>1004005 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDSTATEMENTOFOPERATIONSUNAUDITED" roleURI="http://portillos.com/role/CONDENSEDCONSOLIDATEDSTATEMENTOFOPERATIONSUNAUDITED">
        <link:definition>1005006 - Statement - CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (UNAUDITED)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINREDEEMABLEPREFERREDUNITSANDEQUITYUNAUDITED" roleURI="http://portillos.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINREDEEMABLEPREFERREDUNITSANDEQUITYUNAUDITED">
        <link:definition>1006007 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE PREFERRED UNITS AND EQUITY (UNAUDITED)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKHOLDERSEQUITY" roleURI="http://portillos.com/role/STOCKHOLDERSEQUITY">
        <link:definition>2101101 - Disclosure - STOCKHOLDERS' EQUITY</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKHOLDERSEQUITYDetails" roleURI="http://portillos.com/role/STOCKHOLDERSEQUITYDetails">
        <link:definition>2402401 - Disclosure - STOCKHOLDERS' EQUITY (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" roleURI="http://portillos.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED">
        <link:definition>1007008 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DESCRIPTIONOFBUSINESS" roleURI="http://portillos.com/role/DESCRIPTIONOFBUSINESS">
        <link:definition>2103102 - Disclosure - DESCRIPTION OF BUSINESS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DESCRIPTIONOFBUSINESSDetails" roleURI="http://portillos.com/role/DESCRIPTIONOFBUSINESSDetails">
        <link:definition>2404402 - Disclosure - DESCRIPTION OF BUSINESS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES" roleURI="http://portillos.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES">
        <link:definition>2105103 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies" roleURI="http://portillos.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies">
        <link:definition>2206201 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" roleURI="http://portillos.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails">
        <link:definition>2407403 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUERECOGNITION" roleURI="http://portillos.com/role/REVENUERECOGNITION">
        <link:definition>2108104 - Disclosure - REVENUE RECOGNITION</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUERECOGNITIONTables" roleURI="http://portillos.com/role/REVENUERECOGNITIONTables">
        <link:definition>2309301 - Disclosure - REVENUE RECOGNITION (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUERECOGNITIONDetails" roleURI="http://portillos.com/role/REVENUERECOGNITIONDetails">
        <link:definition>2410404 - Disclosure - REVENUE RECOGNITION (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FAIRVALUEOFFINANCIALINSTRUMENTS" roleURI="http://portillos.com/role/FAIRVALUEOFFINANCIALINSTRUMENTS">
        <link:definition>2111105 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FAIRVALUEOFFINANCIALINSTRUMENTSTables" roleURI="http://portillos.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSTables">
        <link:definition>2312302 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FAIRVALUEOFFINANCIALINSTRUMENTSDetails" roleURI="http://portillos.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSDetails">
        <link:definition>2413405 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVENTORIES" roleURI="http://portillos.com/role/INVENTORIES">
        <link:definition>2114106 - Disclosure - INVENTORIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVENTORIESTables" roleURI="http://portillos.com/role/INVENTORIESTables">
        <link:definition>2315303 - Disclosure - INVENTORIES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVENTORIESDetails" roleURI="http://portillos.com/role/INVENTORIESDetails">
        <link:definition>2416406 - Disclosure - INVENTORIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PROPERTYEQUIPMENTNET" roleURI="http://portillos.com/role/PROPERTYEQUIPMENTNET">
        <link:definition>2117107 - Disclosure - PROPERTY &amp; EQUIPMENT, NET</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PROPERTYEQUIPMENTNETTables" roleURI="http://portillos.com/role/PROPERTYEQUIPMENTNETTables">
        <link:definition>2318304 - Disclosure - PROPERTY &amp; EQUIPMENT, NET (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PROPERTYEQUIPMENTNETDetails" roleURI="http://portillos.com/role/PROPERTYEQUIPMENTNETDetails">
        <link:definition>2419407 - Disclosure - PROPERTY &amp; EQUIPMENT, NET (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLINTANGIBLEASSETS" roleURI="http://portillos.com/role/GOODWILLINTANGIBLEASSETS">
        <link:definition>2120108 - Disclosure - GOODWILL &amp; INTANGIBLE ASSETS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLINTANGIBLEASSETSTables" roleURI="http://portillos.com/role/GOODWILLINTANGIBLEASSETSTables">
        <link:definition>2321305 - Disclosure - GOODWILL &amp; INTANGIBLE ASSETS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLINTANGIBLEASSETSSummaryofIntangibleAssetsNetDetails" roleURI="http://portillos.com/role/GOODWILLINTANGIBLEASSETSSummaryofIntangibleAssetsNetDetails">
        <link:definition>2422408 - Disclosure - GOODWILL &amp; INTANGIBLE ASSETS - Summary of Intangible Assets, Net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLINTANGIBLEASSETSSummaryofIntangibleAssetsNetDetails_1" roleURI="http://portillos.com/role/GOODWILLINTANGIBLEASSETSSummaryofIntangibleAssetsNetDetails_1">
        <link:definition>2422408 - Disclosure - GOODWILL &amp; INTANGIBLE ASSETS - Summary of Intangible Assets, Net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLINTANGIBLEASSETSNarrativeDetails" roleURI="http://portillos.com/role/GOODWILLINTANGIBLEASSETSNarrativeDetails">
        <link:definition>2423409 - Disclosure - GOODWILL &amp; INTANGIBLE ASSETS - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EQUITYMETHODINVESTMENT" roleURI="http://portillos.com/role/EQUITYMETHODINVESTMENT">
        <link:definition>2124109 - Disclosure - EQUITY METHOD INVESTMENT</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EQUITYMETHODINVESTMENTTables" roleURI="http://portillos.com/role/EQUITYMETHODINVESTMENTTables">
        <link:definition>2325306 - Disclosure - EQUITY METHOD INVESTMENT (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EQUITYMETHODINVESTMENTDetails" roleURI="http://portillos.com/role/EQUITYMETHODINVESTMENTDetails">
        <link:definition>2426410 - Disclosure - EQUITY METHOD INVESTMENT (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBT" roleURI="http://portillos.com/role/DEBT">
        <link:definition>2127110 - Disclosure - DEBT</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTTables" roleURI="http://portillos.com/role/DEBTTables">
        <link:definition>2328307 - Disclosure - DEBT (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTSummaryofDebtDetails" roleURI="http://portillos.com/role/DEBTSummaryofDebtDetails">
        <link:definition>2429411 - Disclosure - DEBT - Summary of Debt (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTSummaryofDebtDetails_1" roleURI="http://portillos.com/role/DEBTSummaryofDebtDetails_1">
        <link:definition>2429411 - Disclosure - DEBT - Summary of Debt (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTNarrativeDetails" roleURI="http://portillos.com/role/DEBTNarrativeDetails">
        <link:definition>2430412 - Disclosure - DEBT - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REDEEMABLEPREFERREDUNITS" roleURI="http://portillos.com/role/REDEEMABLEPREFERREDUNITS">
        <link:definition>2131111 - Disclosure - REDEEMABLE PREFERRED UNITS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REDEEMABLEPREFERREDUNITSDetails" roleURI="http://portillos.com/role/REDEEMABLEPREFERREDUNITSDetails">
        <link:definition>2432413 - Disclosure - REDEEMABLE PREFERRED UNITS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="COMMONUNITSANDUNITBASEDCOMPENSATION" roleURI="http://portillos.com/role/COMMONUNITSANDUNITBASEDCOMPENSATION">
        <link:definition>2133112 - Disclosure - COMMON UNITS AND UNIT-BASED COMPENSATION</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="COMMONUNITSANDUNITBASEDCOMPENSATIONDetails" roleURI="http://portillos.com/role/COMMONUNITSANDUNITBASEDCOMPENSATIONDetails">
        <link:definition>2434414 - Disclosure - COMMON UNITS AND UNIT-BASED COMPENSATION (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONTINGENCIES" roleURI="http://portillos.com/role/CONTINGENCIES">
        <link:definition>2135113 - Disclosure - CONTINGENCIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONTINGENCIESDetails" roleURI="http://portillos.com/role/CONTINGENCIESDetails">
        <link:definition>2436415 - Disclosure - CONTINGENCIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RELATEDPARTYTRANSACTIONS" roleURI="http://portillos.com/role/RELATEDPARTYTRANSACTIONS">
        <link:definition>2137114 - Disclosure - RELATED PARTY TRANSACTIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RELATEDPARTYTRANSACTIONSDetails" roleURI="http://portillos.com/role/RELATEDPARTYTRANSACTIONSDetails">
        <link:definition>2438416 - Disclosure - RELATED PARTY TRANSACTIONS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSLOSSPERUNIT" roleURI="http://portillos.com/role/EARNINGSLOSSPERUNIT">
        <link:definition>2139115 - Disclosure - EARNINGS (LOSS) PER UNIT</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSLOSSPERUNITTables" roleURI="http://portillos.com/role/EARNINGSLOSSPERUNITTables">
        <link:definition>2340308 - Disclosure - EARNINGS (LOSS) PER UNIT (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSLOSSPERUNITScheduleofBasicandDilutedEarningsLossperUnitDetails" roleURI="http://portillos.com/role/EARNINGSLOSSPERUNITScheduleofBasicandDilutedEarningsLossperUnitDetails">
        <link:definition>2441417 - Disclosure - EARNINGS (LOSS) PER UNIT - Schedule of Basic and Diluted Earnings (Loss) per Unit (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSLOSSPERUNITScheduleofUnitsExcludedfromCalculationofDilutedEarningsperShareDetails" roleURI="http://portillos.com/role/EARNINGSLOSSPERUNITScheduleofUnitsExcludedfromCalculationofDilutedEarningsperShareDetails">
        <link:definition>2442418 - Disclosure - EARNINGS (LOSS) PER UNIT - Schedule of Units Excluded from Calculation of Diluted Earnings per Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUBSEQUENTEVENTS" roleURI="http://portillos.com/role/SUBSEQUENTEVENTS">
        <link:definition>2143116 - Disclosure - SUBSEQUENT EVENTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUBSEQUENTEVENTSDetails" roleURI="http://portillos.com/role/SUBSEQUENTEVENTSDetails">
        <link:definition>2444419 - Disclosure - SUBSEQUENT EVENTS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="ptlo_TemporaryEquityPercentAccretionPerYear" abstract="false" name="TemporaryEquityPercentAccretionPerYear" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_SecondLienTermB3LoansMember" abstract="true" name="SecondLienTermB3LoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_A2021PlanMember" abstract="true" name="A2021PlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_AmortizationOfDeferredLeaseIncentives" abstract="false" name="AmortizationOfDeferredLeaseIncentives" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_AntidilutiveUnitsMember" abstract="true" name="AntidilutiveUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_PaymentsForShareBasedAwardsCashBonus" abstract="false" name="PaymentsForShareBasedAwardsCashBonus" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_CommonStockSharesSubscribedButUnissuedRepaymentOfSubscriptionReceivable" abstract="false" name="CommonStockSharesSubscribedButUnissuedRepaymentOfSubscriptionReceivable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_LineOfCreditFacilityFrontingFeePercentage" abstract="false" name="LineOfCreditFacilityFrontingFeePercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_TemporaryEquityPreferredRateDomain" abstract="true" name="TemporaryEquityPreferredRateDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_NumberOfFoodProductionCommissaries" abstract="false" name="NumberOfFoodProductionCommissaries" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="ptlo_COChicagoLLCMember" abstract="true" name="COChicagoLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_LineOfCreditFacilityAccordionFeatureIncreaseLimit" abstract="false" name="LineOfCreditFacilityAccordionFeatureIncreaseLimit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_PaymentOfStockIssuanceCostsOfferingCosts" abstract="false" name="PaymentOfStockIssuanceCostsOfferingCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_NumberOfLeasedProperties" abstract="false" name="NumberOfLeasedProperties" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="ptlo_FirstLienTermB3LoansMember" abstract="true" name="FirstLienTermB3LoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_ProceedsFromPaycheckProtectionProgramLoanCARESAct" abstract="false" name="ProceedsFromPaycheckProtectionProgramLoanCARESAct" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_TaxReceivableAgreementTaxSavingsRetainedAsAPercent" abstract="false" name="TaxReceivableAgreementTaxSavingsRetainedAsAPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_ConsultingFeesAnnualContractualAmount" abstract="false" name="ConsultingFeesAnnualContractualAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_TemporaryEquityLiquidationPreferencePercent" abstract="false" name="TemporaryEquityLiquidationPreferencePercent" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_NumberOfNonTraditionalRestaurant" abstract="false" name="NumberOfNonTraditionalRestaurant" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="ptlo_TaxReceivableAgreementTaxPayableAsAPercentOfTaxSavings" abstract="false" name="TaxReceivableAgreementTaxPayableAsAPercentOfTaxSavings" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_PreferredRateAnnualIncreaseUntilEighthAnniversaryMember" abstract="true" name="PreferredRateAnnualIncreaseUntilEighthAnniversaryMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_TemporaryEquityIncreaseToPreferredRateDueToTriggeringEventPercent" abstract="false" name="TemporaryEquityIncreaseToPreferredRateDueToTriggeringEventPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_DeferredRevenueGiftCardSalesThatWillNotBeRedeemedPercent" abstract="false" name="DeferredRevenueGiftCardSalesThatWillNotBeRedeemedPercent" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_IncreaseDecreaseInDeferredLeaseIncentives" abstract="false" name="IncreaseDecreaseInDeferredLeaseIncentives" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_OfferingCostsIncurredButNotYetPaid" abstract="false" name="OfferingCostsIncurredButNotYetPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_TemporaryEquityTextBlock" abstract="false" name="TemporaryEquityTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="ptlo_PortillosIncMember" abstract="true" name="PortillosIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_PreferredRateAnnualIncreaseEighthToTenthAnniversaryMember" abstract="true" name="PreferredRateAnnualIncreaseEighthToTenthAnniversaryMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_TemporaryEquityPreferredRateAxis" abstract="true" name="TemporaryEquityPreferredRateAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="ptlo_TermLoanMember" abstract="true" name="TermLoanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_NumberOfRestaurantsOpenedDuringPeriod" abstract="false" name="NumberOfRestaurantsOpenedDuringPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="ptlo_GiftCardBreakage" abstract="false" name="GiftCardBreakage" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_FormerCEOMember" abstract="true" name="FormerCEOMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_ProceedsFromDispositionOfAssetsNetTradeInValue" abstract="false" name="ProceedsFromDispositionOfAssetsNetTradeInValue" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_DebtInstrumentIncreaseDecreaseInBasisSpreadOnVariableRate" abstract="false" name="DebtInstrumentIncreaseDecreaseInBasisSpreadOnVariableRate" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="ptlo_RepaymentOfStockSubscriptionReceivable" abstract="false" name="RepaymentOfStockSubscriptionReceivable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="ptlo_PreferredRateAnnualIncreaseThereafterMember" abstract="true" name="PreferredRateAnnualIncreaseThereafterMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_GiftCardMember" abstract="true" name="GiftCardMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ptlo_CommonStockShareSubscribedButUnissuedSubscriptionsReceived" abstract="false" name="CommonStockShareSubscribedButUnissuedSubscriptionsReceived" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
