<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001896086</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>
                <ns2:street1>255 Fiserv Drive</ns2:street1>
                <ns2:city>Brookfield</ns2:city>
                <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                <ns2:zipCode>53045</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>262-879-5000</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>SUZAN KEREERE &amp; KHAM H KEREERE JT TEN</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>38th Fl.</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>1633</noOfUnitsSold>
            <aggregateMarketValue>216519.47</aggregateMarketValue>
            <noOfUnitsOutstanding>600185716</noOfUnitsOutstanding>
            <approxSaleDate>12/27/2023</approxSaleDate>
            <securitiesExchangeName>NYSE</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/28/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1633</amountOfSecuritiesAcquired>
            <paymentDate>06/28/2022</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <remarks>The securities to be sold were acquired upon the vesting of restricted stock units on 06/28/2022 and 02/23/2023.</remarks>
        <noticeSignature>
            <noticeDate>12/27/2023</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>09/18/2023</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Suzan Kereere</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
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144
0001896086
XXXXXXXX
LIVE
0000798354
FISERV INC
001-38962
255 Fiserv Drive
Brookfield
WI
53045
262-879-5000
SUZAN KEREERE & KHAM H KEREERE JT TEN
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
38th Fl.
New York
NY
10004
1633
216519.47
600185716
12/27/2023
NYSE
Common
06/28/2022
Restricted Stock Units
Issuer
N
1633
06/28/2022
N/A
Y
The securities to be sold were acquired upon the vesting of restricted stock units on 06/28/2022 and 02/23/2023.
12/27/2023
09/18/2023
/s/ Suzan Kereere