<SEC-DOCUMENT>0000831641-20-000133.txt : 20201120
<SEC-HEADER>0000831641-20-000133.hdr.sgml : 20201120
<ACCEPTANCE-DATETIME>20201120180700
ACCESSION NUMBER:		0000831641-20-000133
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20201118
FILED AS OF DATE:		20201120
DATE AS OF CHANGE:		20201120

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Argus Roger R
		CENTRAL INDEX KEY:			0001721930

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19655
		FILM NUMBER:		201333721

	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]
		IRS NUMBER:				954148514
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0927

	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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    <footnotes>
        <footnote id="F1">Shares automatically acquired upon the vesting of restricted stock units (RSUs).</footnote>
        <footnote id="F2">Shares acquired pursuant to vesting of performance stock units (PSUs) earned under 2015 Equity Incentive Plan.</footnote>
        <footnote id="F3">Represents the combined number of shares withheld to pay the related tax liability on a total of 6,878 performance stock units (PSUs) and 1,771  restricted stock units (RSUs) which vested on 11/18/2020.</footnote>
        <footnote id="F4">$120.9834 is an average price. Shares were sold at prices ranging from $120.96 to $121.08 per share.</footnote>
        <footnote id="F5">The option becomes exercisable as to 25% of the Shares on each anniversary of the grant date.</footnote>
        <footnote id="F6">The restricted stock units (RSUs) become vested as to 25% of the shares underlying the RSUs on November 18, 2019, and on each of anniversary of that date until the RSUs are fully vested.</footnote>
        <footnote id="F7">The RSUs become vested as to 25% of the shares on November 18, 2020, and the anniversary of that date going forward until fully vested.</footnote>
        <footnote id="F8">The RSUs become vested as to 25% of the shares on November 18, 2021, and the anniversary of that date going forward until fully vested.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Preston Hopson, Attorney-in-fact for Roger R. Argus</signatureName>
        <signatureDate>2020-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</SEC-DOCUMENT>
