<SEC-DOCUMENT>0001972362-23-001052.txt : 20231128
<SEC-HEADER>0001972362-23-001052.hdr.sgml : 20231128
<ACCEPTANCE-DATETIME>20231128173817
ACCESSION NUMBER:		0001972362-23-001052
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20231128
DATE AS OF CHANGE:		20231128

SUBJECT COMPANY:	

	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:			1001

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	000-19655
		FILM NUMBER:		231447713

	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

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BATRACK DAN L
		CENTRAL INDEX KEY:			0001207854

	FILING VALUES:
		FORM TYPE:		144

	MAIL ADDRESS:	
		STREET 1:		TETRA TECH, INC.
		STREET 2:		3475 EAST FOOTHILL BOULEVARD
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91107
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001207854</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0000831641</issuerCik>
      <issuerName>TETRA TECH INC</issuerName>
      <secFileNumber>000-19655</secFileNumber>
      <issuerAddress>
        <com:street1>3475 EAST FOOTHILL BOULEVARD</com:street1>
        <com:city>PASADENA</com:city>
        <com:stateOrCountry>CA</com:stateOrCountry>
        <com:zipCode>91107</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>6263514664</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>BATRACK DAN L</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>MORGAN STANLEY SMITH BARNEY LLC EXECUTIVE SERVICES</name>
        <address>
          <com:street1>200 W CIVIC CENTER DR. 4TH FLOOR</com:street1>
          <com:city>SANDY</com:city>
          <com:stateOrCountry>UT</com:stateOrCountry>
          <com:zipCode>84070</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>22000</noOfUnitsSold>
      <aggregateMarketValue>3553303.51</aggregateMarketValue>
      <noOfUnitsOutstanding>53200000</noOfUnitsOutstanding>
      <approxSaleDate>11/28/2023</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <acquiredDate>11/18/2022</acquiredDate>
      <natureOfAcquisitionTransaction>RESTRICTED STOCK</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ISSUER</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>1395</amountOfSecuritiesAcquired>
      <paymentDate>11/18/2022</paymentDate>
      <natureOfPayment>COMPENSATION</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <acquiredDate>11/18/2023</acquiredDate>
      <natureOfAcquisitionTransaction>RESTRICTED STOCK</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ISSUER</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>5080</amountOfSecuritiesAcquired>
      <paymentDate>11/18/2023</paymentDate>
      <natureOfPayment>COMPENSATION</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <acquiredDate>11/21/2023</acquiredDate>
      <natureOfAcquisitionTransaction>PERFORMANCE SHARES</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ISSUER</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>15525</amountOfSecuritiesAcquired>
      <paymentDate>11/21/2023</paymentDate>
      <natureOfPayment>COMPENSATION</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>11/28/2023</noticeDate>
      <signature>/s/ Danny Lee Batrack</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
