<?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>0001560814</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001169561</issuerCik>
            <issuerName>COMMVAULT SYSTEMS INC.</issuerName>
            <secFileNumber>001-33026</secFileNumber>
            <issuerAddress>
                <ns2:street1>1 Commvault Way</ns2:street1>
                <ns2:city>Tinton Falls</ns2:city>
                <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                <ns2:zipCode>07724</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>(732) 870-4000</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>GARY MERRILL</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>E*TRADE FINANCIAL CORPORATION</name>
                <address>
                    <ns2:street1>3 EDISON DRIVE</ns2:street1>
                    <ns2:city>ALPHARETTA</ns2:city>
                    <ns2:stateOrCountry>GA</ns2:stateOrCountry>
                    <ns2:zipCode>30005</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>1322</noOfUnitsSold>
            <aggregateMarketValue>88018.76</aggregateMarketValue>
            <noOfUnitsOutstanding>43973836</noOfUnitsOutstanding>
            <approxSaleDate>05/24/2023</approxSaleDate>
            <securitiesExchangeName>NASD</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>05/22/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>233</amountOfSecuritiesAcquired>
            <paymentDate>05/22/2023</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>05/22/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Performance Shares</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1089</amountOfSecuritiesAcquired>
            <paymentDate>05/22/2023</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>GARY MERRILL</name>
                <address>
                    <ns2:street1>1 Commvault Way</ns2:street1>
                    <ns2:city>Tinton Falls</ns2:city>
                    <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                    <ns2:zipCode>07724</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/23/2023</saleDate>
            <amountOfSecuritiesSold>341</amountOfSecuritiesSold>
            <grossProceeds>22789.03</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>GARY MERRILL</name>
                <address>
                    <ns2:street1>1 Commvault Way</ns2:street1>
                    <ns2:city>Tinton Falls</ns2:city>
                    <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                    <ns2:zipCode>07724</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2023</saleDate>
            <amountOfSecuritiesSold>982</amountOfSecuritiesSold>
            <grossProceeds>64812.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>GARY MERRILL</name>
                <address>
                    <ns2:street1>1 Commvault Way</ns2:street1>
                    <ns2:city>Tinton Falls</ns2:city>
                    <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                    <ns2:zipCode>07724</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/18/2023</saleDate>
            <amountOfSecuritiesSold>2235</amountOfSecuritiesSold>
            <grossProceeds>143665.80</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>GARY MERRILL</name>
                <address>
                    <ns2:street1>1 Commvault Way</ns2:street1>
                    <ns2:city>Tinton Falls</ns2:city>
                    <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                    <ns2:zipCode>07724</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>05/17/2023</saleDate>
            <amountOfSecuritiesSold>3761</amountOfSecuritiesSold>
            <grossProceeds>238703.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>GARY MERRILL</name>
                <address>
                    <ns2:street1>1 Commvault Way</ns2:street1>
                    <ns2:city>Tinton Falls</ns2:city>
                    <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                    <ns2:zipCode>07724</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>03/06/2023</saleDate>
            <amountOfSecuritiesSold>4492</amountOfSecuritiesSold>
            <grossProceeds>264475.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>05/24/2023</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>02/03/2023</planAdoptionDate>
            </planAdoptionDates>
            <signature>GARY MERRILL</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 7244}]
144
0001560814
XXXXXXXX
LIVE
0001169561
COMMVAULT SYSTEMS INC.
001-33026
1 Commvault Way
Tinton Falls
NJ
07724
(732) 870-4000
GARY MERRILL
Officer
Common
E*TRADE FINANCIAL CORPORATION
3 EDISON DRIVE
ALPHARETTA
GA
30005
1322
88018.76
43973836
05/24/2023
NASD
Common
05/22/2023
Restricted Stock
Issuer
N
233
05/22/2023
Not Applicable
Common
05/22/2023
Performance Shares
Issuer
N
1089
05/22/2023
Not Applicable
N
GARY MERRILL
1 Commvault Way
Tinton Falls
NJ
07724
Common
05/23/2023
341
22789.03
GARY MERRILL
1 Commvault Way
Tinton Falls
NJ
07724
Common
05/19/2023
982
64812.00
GARY MERRILL
1 Commvault Way
Tinton Falls
NJ
07724
Common
05/18/2023
2235
143665.80
GARY MERRILL
1 Commvault Way
Tinton Falls
NJ
07724
COMMON
05/17/2023
3761
238703.00
GARY MERRILL
1 Commvault Way
Tinton Falls
NJ
07724
COMMON
03/06/2023
4492
264475.00
05/24/2023
02/03/2023
GARY MERRILL