<SEC-DOCUMENT>0001104659-17-002819-index.html : 20170118
<SEC-HEADER>0001104659-17-002819.hdr.sgml : 20170118
<ACCEPTANCE-DATETIME>20170118170045
ACCESSION NUMBER:		0001104659-17-002819
CONFORMED SUBMISSION TYPE:	DEFA14A
PUBLIC DOCUMENT COUNT:		5
FILED AS OF DATE:		20170118
DATE AS OF CHANGE:		20170118
EFFECTIVENESS DATE:		20170118

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:		DEFA14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19655
		FILM NUMBER:		17533994

	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>DEFA14A
<SEQUENCE>1
<FILENAME>a17-2497_3defa14a.htm
<DESCRIPTION>DEFA14A
<TEXT>
Document 1 - file: a17-2497_3defa14a.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g24973bii001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g24973bii001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g24973bii002.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g24973bii002.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g24973bii003.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g24973bii003.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>g24973bii004.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g24973bii004.jpg

</DOCUMENT>
</SEC-DOCUMENT>