content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001654667</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0000798354</issuerCik>
        <issuerName>FISERV INC</issuerName>
        <secFileNumber>001-38962</secFileNumber>
        <issuerAddress>
          <com:street1>255 FISERV DR</com:street1>
          <com:street2>PO BOX 979</com:street2>
          <com:city>BROOKFIELD</com:city>
          <com:stateOrCountry>WI</com:stateOrCountry>
          <com:zipCode>53045</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>4148795000</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Chiarello Guy</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Merrill Lynch</name>
          <address>
            <com:street1>3455 Peachtree Rd NE</com:street1>
            <com:street2>STE 1000</com:street2>
            <com:city>Atlanta</com:city>
            <com:stateOrCountry>GA</com:stateOrCountry>
            <com:zipCode>30326</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>80000</noOfUnitsSold>
        <aggregateMarketValue>10725391.00</aggregateMarketValue>
        <noOfUnitsOutstanding>600185716</noOfUnitsOutstanding>
        <approxSaleDate>12/12/2023</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>12/12/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Exercise of a Stock Award</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>FISERV, INC.</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>80000</amountOfSecuritiesAcquired>
        <paymentDate>12/12/2023</paymentDate>
        <natureOfPayment>Compensatory Payment</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Guy Chiarello</name>
          <address>
            <com:street1>255 Fiserv Drive</com:street1>
            <com:city>Brookfield</com:city>
            <com:stateOrCountry>WI</com:stateOrCountry>
            <com:zipCode>53045</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <saleDate>10/02/2023</saleDate>
        <amountOfSecuritiesSold>6750</amountOfSecuritiesSold>
        <grossProceeds>757148.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Guy Chiarello</name>
          <address>
            <com:street1>255 Fiserv Drive</com:street1>
            <com:city>Brookfield</com:city>
            <com:stateOrCountry>WI</com:stateOrCountry>
            <com:zipCode>53045</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <saleDate>11/01/2023</saleDate>
        <amountOfSecuritiesSold>6750</amountOfSecuritiesSold>
        <grossProceeds>768825.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Guy Chiarello</name>
          <address>
            <com:street1>255 Fiserv Drive</com:street1>
            <com:city>Brookfield</com:city>
            <com:stateOrCountry>WI</com:stateOrCountry>
            <com:zipCode>53045</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <saleDate>12/01/2023</saleDate>
        <amountOfSecuritiesSold>6750</amountOfSecuritiesSold>
        <grossProceeds>876893.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>12/12/2023</noticeDate>
        <signature>Guy Chiarello</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4538}]
text: 144
  0001654667
  XXXXXXXX
  LIVE
  0000798354
  FISERV INC
  001-38962
  255 FISERV DR
  PO BOX 979
  BROOKFIELD
  WI
  53045
  4148795000
  Chiarello Guy
  Officer
  Common
  Merrill Lynch
  3455 Peachtree Rd NE
  STE 1000
  Atlanta
  GA
  30326
  80000
  10725391.00
  600185716
  12/12/2023
  NYSE
  Common
  12/12/2023
  Exercise of a Stock Award
  FISERV, INC.
  N
  80000
  12/12/2023
  Compensatory Payment
  N
  Guy Chiarello
  255 Fiserv Drive
  Brookfield
  WI
  53045
  Common
  10/02/2023
  6750
  757148.00
  Guy Chiarello
  255 Fiserv Drive
  Brookfield
  WI
  53045
  Common
  11/01/2023
  6750
  768825.00
  Guy Chiarello
  255 Fiserv Drive
  Brookfield
  WI
  53045
  Common
  12/01/2023
  6750
  876893.00
  12/12/2023
  Guy Chiarello