    <SEC-DOCUMENT>0001104659-24-004804-index.html : 20240118
    <SEC-HEADER>0001104659-24-004804.hdr.sgml : 20240118
    <ACCEPTANCE-DATETIME>20240118160619
    ACCESSION NUMBER:		0001104659-24-004804
    CONFORMED SUBMISSION TYPE:	ARS
    PUBLIC DOCUMENT COUNT:		1
    CONFORMED PERIOD OF REPORT:	20231001
    FILED AS OF DATE:		20240118
    DATE AS OF CHANGE:		20240118
    EFFECTIVENESS DATE:		20240118

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			TETRA TECH INC
    		CENTRAL INDEX KEY:			0000831641
    		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ENGINEERING SERVICES [8711]
    		ORGANIZATION NAME:           	07 Trade & Services
    		IRS NUMBER:				954148514
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1001

    	FILING VALUES:
    		FORM TYPE:		ARS
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-19655
    		FILM NUMBER:		24541831

    	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>ARS
    <SEQUENCE>1
    <FILENAME>tm242152d4_ars.pdf
    <DESCRIPTION>ARS
    <TEXT>
    Document 1 - file: tm242152d4_ars.pdf

    </DOCUMENT>
    </SEC-DOCUMENT>