<?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>0001346629</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>600 N. Vel R. Phillips Avenue</ns2:street1>
                <ns2:city>Milwaukee</ns2:city>
                <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                <ns2:zipCode>53203</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>262- 879-5000</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>FRANK J BISIGNANO</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Former Affiliate</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>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>584500</noOfUnitsSold>
            <aggregateMarketValue>98555409.05</aggregateMarketValue>
            <noOfUnitsOutstanding>554433824</noOfUnitsOutstanding>
            <approxSaleDate>05/19/2025</approxSaleDate>
            <securitiesExchangeName>NYSE</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/29/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>515</amountOfSecuritiesAcquired>
            <paymentDate>11/29/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/29/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>10</amountOfSecuritiesAcquired>
            <paymentDate>11/29/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/23/2021</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>9711</amountOfSecuritiesAcquired>
            <paymentDate>11/23/2021</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/15/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>62438</amountOfSecuritiesAcquired>
            <paymentDate>08/15/2019</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>01/29/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>14352</amountOfSecuritiesAcquired>
            <paymentDate>01/29/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/24/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>41051</amountOfSecuritiesAcquired>
            <paymentDate>02/24/2019</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>07/29/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>21382</amountOfSecuritiesAcquired>
            <paymentDate>07/29/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/15/2018</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>150182</amountOfSecuritiesAcquired>
            <paymentDate>08/15/2018</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/15/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>50444</amountOfSecuritiesAcquired>
            <paymentDate>08/15/2019</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/26/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>6098</amountOfSecuritiesAcquired>
            <paymentDate>02/26/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/26/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>4</amountOfSecuritiesAcquired>
            <paymentDate>02/26/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/15/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>15314</amountOfSecuritiesAcquired>
            <paymentDate>02/15/2019</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>07/29/2020</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>24432</amountOfSecuritiesAcquired>
            <paymentDate>07/29/2020</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/15/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>25142</amountOfSecuritiesAcquired>
            <paymentDate>02/15/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>07/31/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>65649</amountOfSecuritiesAcquired>
            <paymentDate>07/31/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/20/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>29054</amountOfSecuritiesAcquired>
            <paymentDate>02/20/2019</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/15/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>494</amountOfSecuritiesAcquired>
            <paymentDate>02/15/2019</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/15/2020</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>68228</amountOfSecuritiesAcquired>
            <paymentDate>08/15/2020</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>Frank Bisignano</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/16/2025</saleDate>
            <amountOfSecuritiesSold>100000</amountOfSecuritiesSold>
            <grossProceeds>16683943.50</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>On May 19, 2025, the client entered into a covered call transaction in which they sold 5,845 FI calls.</remarks>
        <noticeSignature>
            <noticeDate>05/19/2025</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Frank J Bisignano</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 14646}]
144
0001346629
XXXXXXXX
LIVE
0000798354
FISERV, INC.
001-38962
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
262- 879-5000
FRANK J BISIGNANO
Former Affiliate
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
584500
98555409.05
554433824
05/19/2025
NYSE
Common
11/29/2022
Restricted stock vesting under a registered plan
Issuer
N
515
11/29/2022
Not Applicable
Common
11/29/2022
Restricted stock vesting under a registered plan
Issuer
N
10
11/29/2022
Not Applicable
Common
11/23/2021
Restricted stock vesting under a registered plan
Issuer
N
9711
11/23/2021
Not Applicable
Common
08/15/2019
Restricted stock vesting under a registered plan
Issuer
N
62438
08/15/2019
Not Applicable
Common
01/29/2022
Restricted stock vesting under a registered plan
Issuer
N
14352
01/29/2022
Not Applicable
Common
02/24/2019
Restricted stock vesting under a registered plan
Issuer
N
41051
02/24/2019
Not Applicable
Common
07/29/2022
Restricted stock vesting under a registered plan
Issuer
N
21382
07/29/2022
Not Applicable
Common
08/15/2018
Restricted stock vesting under a registered plan
Issuer
N
150182
08/15/2018
Not Applicable
Common
08/15/2019
Restricted stock vesting under a registered plan
Issuer
N
50444
08/15/2019
Not Applicable
Common
02/26/2022
Restricted stock vesting under a registered plan
Issuer
N
6098
02/26/2022
Not Applicable
Common
02/26/2022
Restricted stock vesting under a registered plan
Issuer
N
4
02/26/2022
Not Applicable
Common
02/15/2019
Restricted stock vesting under a registered plan
Issuer
N
15314
02/15/2019
Not Applicable
Common
07/29/2020
Restricted stock vesting under a registered plan
Issuer
N
24432
07/29/2020
Not Applicable
Common
02/15/2022
Restricted stock vesting under a registered plan
Issuer
N
25142
02/15/2022
Not Applicable
Common
07/31/2022
Restricted stock vesting under a registered plan
Issuer
N
65649
07/31/2022
Not Applicable
Common
02/20/2019
Restricted stock vesting under a registered plan
Issuer
N
29054
02/20/2019
Not Applicable
Common
02/15/2019
Restricted stock vesting under a registered plan
Issuer
N
494
02/15/2019
Not Applicable
Common
08/15/2020
Restricted stock vesting under a registered plan
Issuer
N
68228
08/15/2020
Not Applicable
N
Frank Bisignano
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/16/2025
100000
16683943.50
On May 19, 2025, the client entered into a covered call transaction in which they sold 5,845 FI calls.
05/19/2025
/s/ Frank J Bisignano