<?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>0001471798</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0000007431</issuerCik>
            <issuerName>ARMSTRONG WORLD INDUSTRIES INC.</issuerName>
            <secFileNumber>001-02116</secFileNumber>
            <issuerAddress>
                <ns2:street1>2500 Columbia Avenue</ns2:street1>
                <ns2:city>Lancaster</ns2:city>
                <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                <ns2:zipCode>17603</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>(717) 397-0611</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>JAMES C MELVILLE</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Director</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>5405</noOfUnitsSold>
            <aggregateMarketValue>657792.99</aggregateMarketValue>
            <noOfUnitsOutstanding>43700062</noOfUnitsOutstanding>
            <approxSaleDate>08/05/2024</approxSaleDate>
            <securitiesExchangeName>NYSE</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/24/2013</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1574</amountOfSecuritiesAcquired>
            <paymentDate>06/24/2013</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/23/2014</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1352</amountOfSecuritiesAcquired>
            <paymentDate>06/23/2014</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/25/2012</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>2479</amountOfSecuritiesAcquired>
            <paymentDate>06/25/2012</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>JAMES C MELVILLE</name>
                <address>
                    <ns2:street1>2500 Columbia Avenue</ns2:street1>
                    <ns2:city>Lancaster</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>17603</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>08/02/2024</saleDate>
            <amountOfSecuritiesSold>5000</amountOfSecuritiesSold>
            <grossProceeds>633344.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>JAMES C MELVILLE</name>
                <address>
                    <ns2:street1>2500 Columbia Avenue</ns2:street1>
                    <ns2:city>Lancaster</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>17603</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>08/02/2024</saleDate>
            <amountOfSecuritiesSold>5000</amountOfSecuritiesSold>
            <grossProceeds>626731.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>08/05/2024</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ James C. Melville</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 5900}]
144
0001471798
XXXXXXXX
LIVE
0000007431
ARMSTRONG WORLD INDUSTRIES INC.
001-02116
2500 Columbia Avenue
Lancaster
PA
17603
(717) 397-0611
JAMES C MELVILLE
Director
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
5405
657792.99
43700062
08/05/2024
NYSE
Common
06/24/2013
Restricted stock vesting under a registered plan
Issuer
N
1574
06/24/2013
Services Rendered
Common
06/23/2014
Restricted stock vesting under a registered plan
Issuer
N
1352
06/23/2014
Services Rendered
Common
06/25/2012
Restricted stock vesting under a registered plan
Issuer
N
2479
06/25/2012
Services Rendered
N
JAMES C MELVILLE
2500 Columbia Avenue
Lancaster
PA
17603
Common
08/02/2024
5000
633344.00
JAMES C MELVILLE
2500 Columbia Avenue
Lancaster
PA
17603
Common
08/02/2024
5000
626731.00
08/05/2024
/s/ James C. Melville