<SEC-DOCUMENT>0000866273-25-000071.txt : 20250917
<SEC-HEADER>0000866273-25-000071.hdr.sgml : 20250917
<ACCEPTANCE-DATETIME>20250917173251
ACCESSION NUMBER:		0000866273-25-000071
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250916
FILED AS OF DATE:		20250917
DATE AS OF CHANGE:		20250917

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHANDLER JOHN D
		CENTRAL INDEX KEY:			0001188020
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15461
		FILM NUMBER:		251321117

	MAIL ADDRESS:	
		STREET 1:		15 EAST 5TH STREET
		STREET 2:		SUITE 1100
		CITY:			TULSA
		STATE:			OK
		ZIP:			74103

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MATRIX SERVICE CO
		CENTRAL INDEX KEY:			0000866273
		STANDARD INDUSTRIAL CLASSIFICATION:	CONSTRUCTION SPECIAL TRADE CONTRACTORS [1700]
		ORGANIZATION NAME:           	05 Real Estate & Construction
		EIN:				731352174
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		15 EAST 5TH STREET
		STREET 2:		SUITE 1100
		CITY:			TULSA
		STATE:			OK
		ZIP:			74103
		BUSINESS PHONE:		9188388822

	MAIL ADDRESS:	
		STREET 1:		15 EAST 5TH STREET
		STREET 2:		SUITE 1100
		CITY:			TULSA
		STATE:			OK
		ZIP:			74103
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1758144769.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-09-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000866273</issuerCik>
        <issuerName>MATRIX SERVICE CO</issuerName>
        <issuerTradingSymbol>MTRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001188020</rptOwnerCik>
            <rptOwnerName>CHANDLER JOHN D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>15 EAST 5TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1100</rptOwnerStreet2>
            <rptOwnerCity>TULSA</rptOwnerCity>
            <rptOwnerState>OK</rptOwnerState>
            <rptOwnerZipCode>74103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <transactionDate>
                <value>2025-09-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.7448</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>78053</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">THE PRICE REPORTED IS A WEIGHTED AVERAGE PRICE.  THESE SHARES WERE PURCHASED IN MULTIPLE TRANSACTIONS AT PRICES RANGING FROM $12.71 TO $12.7851, INCLUSIVE.  THE REPORTING PERSON UNDERTAKES TO PROVIDE TO MATRIX SERVICE COMPANY, ANY SECURITY HOLDER OF MATRIX SERVICE COMPANY, OR THE STAFF OF THE SECURITIES AND EXCHANGE COMMISSION, UPON REQUEST, FULL INFORMATION REGARDING THE NUMBER OF SHARES PURCHASED AT EACH SEPARATE PRICE WITHIN THE RANGE SET FORTH.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>John D. Chandler</signatureName>
        <signatureDate>2025-09-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
