<SEC-DOCUMENT>0001047469-19-000174-index.html : 20190118
<SEC-HEADER>0001047469-19-000174.hdr.sgml : 20190118
<ACCEPTANCE-DATETIME>20190118170051
ACCESSION NUMBER:		0001047469-19-000174
CONFORMED SUBMISSION TYPE:	DEF 14A
PUBLIC DOCUMENT COUNT:		37
CONFORMED PERIOD OF REPORT:	20190228
FILED AS OF DATE:		20190118
DATE AS OF CHANGE:		20190118
EFFECTIVENESS DATE:		20190118

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:			0930

	FILING VALUES:
		FORM TYPE:		DEF 14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19655
		FILM NUMBER:		19533708

	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>DEF 14A
<SEQUENCE>1
<FILENAME>a2237550zdef14a.htm
<DESCRIPTION>DEF 14A
<TEXT>
Document 1 - file: a2237550zdef14a.htm
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>2 <FILENAME>g982825.jpg <DESCRIPTION>G982825.JPG <TEXT> Document 2 - file: g982825.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>3 <FILENAME>g955109.jpg <DESCRIPTION>G955109.JPG <TEXT> Document 3 - file: g955109.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>4 <FILENAME>g189301.jpg <DESCRIPTION>G189301.JPG <TEXT> Document 4 - file: g189301.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>5 <FILENAME>g941210.jpg <DESCRIPTION>G941210.JPG <TEXT> Document 5 - file: g941210.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>6 <FILENAME>g852896.jpg <DESCRIPTION>G852896.JPG <TEXT> Document 6 - file: g852896.jpg
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</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>8 <FILENAME>g653831.jpg <DESCRIPTION>G653831.JPG <TEXT> Document 8 - file: g653831.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>9 <FILENAME>g174764.jpg <DESCRIPTION>G174764.JPG <TEXT> Document 9 - file: g174764.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>10 <FILENAME>g543522.jpg <DESCRIPTION>G543522.JPG <TEXT> Document 10 - file: g543522.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>11 <FILENAME>g81291.jpg <DESCRIPTION>G81291.JPG <TEXT> Document 11 - file: g81291.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>12 <FILENAME>g744023.jpg <DESCRIPTION>G744023.JPG <TEXT> Document 12 - file: g744023.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>13 <FILENAME>g881914.jpg <DESCRIPTION>G881914.JPG <TEXT> Document 13 - file: g881914.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>14 <FILENAME>g105987.jpg <DESCRIPTION>G105987.JPG <TEXT> Document 14 - file: g105987.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>15 <FILENAME>g979372.jpg <DESCRIPTION>G979372.JPG <TEXT> Document 15 - file: g979372.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>16 <FILENAME>g238964.jpg <DESCRIPTION>G238964.JPG <TEXT> Document 16 - file: g238964.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>17 <FILENAME>g112740.jpg <DESCRIPTION>G112740.JPG <TEXT> Document 17 - file: g112740.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>18 <FILENAME>g335595.jpg <DESCRIPTION>G335595.JPG <TEXT> Document 18 - file: g335595.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>19 <FILENAME>g94777.jpg <DESCRIPTION>G94777.JPG <TEXT> Document 19 - file: g94777.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>20 <FILENAME>g147186.jpg <DESCRIPTION>G147186.JPG <TEXT> Document 20 - file: g147186.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>21 <FILENAME>g313616.jpg <DESCRIPTION>G313616.JPG <TEXT> Document 21 - file: g313616.jpg
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</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>23 <FILENAME>g880481.jpg <DESCRIPTION>G880481.JPG <TEXT> Document 23 - file: g880481.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>24 <FILENAME>g1004704.jpg <DESCRIPTION>G1004704.JPG <TEXT> Document 24 - file: g1004704.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>25 <FILENAME>g41829.jpg <DESCRIPTION>G41829.JPG <TEXT> Document 25 - file: g41829.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>26 <FILENAME>g184506.jpg <DESCRIPTION>G184506.JPG <TEXT> Document 26 - file: g184506.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>27 <FILENAME>g74259.jpg <DESCRIPTION>G74259.JPG <TEXT> Document 27 - file: g74259.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>28 <FILENAME>g533138.jpg <DESCRIPTION>G533138.JPG <TEXT> Document 28 - file: g533138.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>29 <FILENAME>g453416.jpg <DESCRIPTION>G453416.JPG <TEXT> Document 29 - file: g453416.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>30 <FILENAME>g1019660.jpg <DESCRIPTION>G1019660.JPG <TEXT> Document 30 - file: g1019660.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>31 <FILENAME>g891780.jpg <DESCRIPTION>G891780.JPG <TEXT> Document 31 - file: g891780.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>32 <FILENAME>g680452.jpg <DESCRIPTION>G680452.JPG <TEXT> Document 32 - file: g680452.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>33 <FILENAME>g724187.jpg <DESCRIPTION>G724187.JPG <TEXT> Document 33 - file: g724187.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>34 <FILENAME>g683679.jpg <DESCRIPTION>G683679.JPG <TEXT> Document 34 - file: g683679.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>35 <FILENAME>g94062.jpg <DESCRIPTION>G94062.JPG <TEXT> Document 35 - file: g94062.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>36 <FILENAME>g67254.jpg <DESCRIPTION>G67254.JPG <TEXT> Document 36 - file: g67254.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>37 <FILENAME>g29792bci001.gif <DESCRIPTION>G29792BCI001.GIF <TEXT> Document 37 - file: g29792bci001.gif
</DOCUMENT> </SEC-DOCUMENT>