<SEC-DOCUMENT>0001104659-18-049514-index.html : 20180803
<SEC-HEADER>0001104659-18-049514.hdr.sgml : 20180803
<ACCEPTANCE-DATETIME>20180803163818
ACCESSION NUMBER:		0001104659-18-049514
CONFORMED SUBMISSION TYPE:	S-8
PUBLIC DOCUMENT COUNT:		3
FILED AS OF DATE:		20180803
DATE AS OF CHANGE:		20180803
EFFECTIVENESS DATE:		20180803

FILER:

	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:			0928

	FILING VALUES:
		FORM TYPE:		S-8
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-226586
		FILM NUMBER:		18992328

	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>S-8
<SEQUENCE>1
<FILENAME>a18-18050_1s8.htm
<DESCRIPTION>S-8
<TEXT>
Document 1 - file: a18-18050_1s8.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>2
<FILENAME>a18-18050_1ex5d1.htm
<DESCRIPTION>EX-5.1
<TEXT>
Document 2 - file: a18-18050_1ex5d1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>3
<FILENAME>a18-18050_1ex23d1.htm
<DESCRIPTION>EX-23.1
<TEXT>
Document 3 - file: a18-18050_1ex23d1.htm

</DOCUMENT>
</SEC-DOCUMENT>