<SEC-DOCUMENT>0001561742-25-000003.txt : 20251202
<SEC-HEADER>0001561742-25-000003.hdr.sgml : 20251202
<ACCEPTANCE-DATETIME>20251202201301
ACCESSION NUMBER:		0001561742-25-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251118
FILED AS OF DATE:		20251202
DATE AS OF CHANGE:		20251202

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CARTER BRIAN N
		CENTRAL INDEX KEY:			0001561742
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19655
		FILM NUMBER:		251544668

	MAIL ADDRESS:	
		STREET 1:		3475 EAST FOOTHILL BOULEVARD
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91107

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TETRA TECH INC
		CENTRAL INDEX KEY:			0000831641
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ENGINEERING SERVICES [8711]
		ORGANIZATION NAME:           	07 Trade & Services
		EIN:				954148514
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0928

	BUSINESS ADDRESS:	
		STREET 1:		3475 EAST FOOTHILL BOULEVARD
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91107
		BUSINESS PHONE:		6263514664

	MAIL ADDRESS:	
		STREET 1:		3475 EAST FOOTHILL BOULEVARD
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91107
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
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<DESCRIPTION>FORM 4
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    <footnotes>
        <footnote id="F1">Represents the shares withheld to pay the related tax liability of the restricted stock units (RSUs) that vested on November 18, 2025.</footnote>
        <footnote id="F2">Shares acquired pursuant to vesting of performance stock units earned under 2018 Equity Incentive Plan.</footnote>
        <footnote id="F3">Represents the shares withheld to pay the related tax liability of performance stock units that vested on November 18, 2025.</footnote>
        <footnote id="F4">Represents the shares withheld to pay the related tax liability of the restricted stock units (RSUs) that vested on November 30, 2025.</footnote>
        <footnote id="F5">Represents an award of RSUs, each unit of which represents a contingent right to receive one share of Tetra Tech common stock.</footnote>
        <footnote id="F6">The RSUs become vested as to 25% of the shares on November 18, 2022, and 25% annually, thereafter, until fully vested.</footnote>
        <footnote id="F7">The RSUs are exercisable at the time of vesting and do not have a set expiration date.</footnote>
        <footnote id="F8">The RSUs become vested as to 25% of the shares on November 18, 2023, and 25% annually, thereafter, until fully vested.</footnote>
        <footnote id="F9">The RSUs become vested as to 25% of the shares on November 30, 2026, and 25% annually, thereafter, until fully vested.</footnote>
        <footnote id="F10">The RSUs become vested as to 25% of the shares on November 30, 2024, and 25% annually, thereafter, until fully vested.</footnote>
        <footnote id="F11">The RSUs become vested as to 25% of the shares on November 30, 2025, and 25% annually, thereafter, until fully vested.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Preston Hopson, Attorney-in-fact for Brian N. Carter</signatureName>
        <signatureDate>2025-12-02</signatureDate>
    </ownerSignature>
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</SEC-DOCUMENT>
