<SEC-DOCUMENT>0001562230-25-000133.txt : 20251113
<SEC-HEADER>0001562230-25-000133.hdr.sgml : 20251113
<ACCEPTANCE-DATETIME>20251113110442
ACCESSION NUMBER:		0001562230-25-000133
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20251113
DATE AS OF CHANGE:		20251113

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CECO ENVIRONMENTAL CORP
		CENTRAL INDEX KEY:			0000003197
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL & COMMERCIAL FANS & BLOWERS & AIR PURIFYING EQUIP [3564]
		ORGANIZATION NAME:           	06 Technology
		EIN:				132566064
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-19763
		FILM NUMBER:		251476246

	BUSINESS ADDRESS:	
		STREET 1:		5080 SPECTRUM DRIVE
		STREET 2:		SUITE 800E
		CITY:			ADDISON
		STATE:			TX
		ZIP:			75001
		BUSINESS PHONE:		(513) 458-2600

	MAIL ADDRESS:	
		STREET 1:		5080 SPECTRUM DRIVE
		STREET 2:		SUITE 800E
		CITY:			ADDISON
		STATE:			TX
		ZIP:			75001

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	API ENTERPRISES INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALARM PRODUCTS INTERNATIONAL INC
		DATE OF NAME CHANGE:	19851210

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Capital International Investors
		CENTRAL INDEX KEY:			0001562230
		ORGANIZATION NAME:           	
		EIN:				951411037
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		333 SOUTH HOPE STREET
		STREET 2:		55TH FL
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071
		BUSINESS PHONE:		213-486-9200

	MAIL ADDRESS:	
		STREET 1:		333 SOUTH HOPE STREET
		STREET 2:		55TH FL
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Capital Research & Management Co - Division 3
		DATE OF NAME CHANGE:	20121114
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
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  <headerData>
    <submissionType>SCHEDULE 13G/A</submissionType>
    <previousAccessionNumber>0001562230-24-000041</previousAccessionNumber>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001562230</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <coverPageHeader>
      <amendmentNo>1</amendmentNo>
      <securitiesClassTitle>Common Stock</securitiesClassTitle>
      <eventDateRequiresFilingThisStatement>09/30/2025</eventDateRequiresFilingThisStatement>
      <issuerInfo>
        <issuerCik>0000003197</issuerCik>
        <issuerName>CECO Environmental Corp.</issuerName>
        <issuerCusip>125141101</issuerCusip>
        <issuerPrincipalExecutiveOfficeAddress>
          <com:street1>5080 SPECTRUM DRIVE</com:street1>
          <com:street2>SUITE 800E</com:street2>
          <com:city>ADDISON</com:city>
          <com:stateOrCountry>X1</com:stateOrCountry>
          <com:zipCode>75001</com:zipCode>
        </issuerPrincipalExecutiveOfficeAddress>
      </issuerInfo>
      <designateRulesPursuantThisScheduleFiled>
        <designateRulePursuantThisScheduleFiled>Rule 13d-1(b)</designateRulePursuantThisScheduleFiled>
      </designateRulesPursuantThisScheduleFiled>
    </coverPageHeader>
    <coverPageHeaderReportingPersonDetails>

      <reportingPersonName>Capital International Investors</reportingPersonName>
      <citizenshipOrOrganization>DE</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>1675351</soleVotingPower>
        <sharedVotingPower>0</sharedVotingPower>
        <soleDispositivePower>1675351</soleDispositivePower>
        <sharedDispositivePower>0</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>1675351.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <classPercent>4.7</classPercent>
      <typeOfReportingPerson>IA</typeOfReportingPerson>
    </coverPageHeaderReportingPersonDetails>
    <items>
      <item1>
        <issuerName>CECO Environmental Corp.</issuerName>
        <issuerPrincipalExecutiveOfficeAddress>5080 SPECTRUM DRIVE, SUITE 800E, ADDISON, TX 75001</issuerPrincipalExecutiveOfficeAddress>
      </item1>
      <item2>
        <filingPersonName>Capital International Investors</filingPersonName>
        <principalBusinessOfficeOrResidenceAddress>333 South Hope Street, 55th Fl, Los Angeles, CA  90071
</principalBusinessOfficeOrResidenceAddress>
        <citizenship>N/A</citizenship>
      </item2>
      <item3>
        <notApplicableFlag>N</notApplicableFlag>
        <typeOfPersonFiling>IA</typeOfPersonFiling>
      </item3>
      <item4>
        <amountBeneficiallyOwned>1,675,351 **

**Capital International Investors ("CII") is a division of Capital Research and Management Company ("CRMC"), as well as its investment management subsidiaries and affiliates Capital Bank and Trust Company, Capital International, Inc., Capital International Limited, Capital International Sarl, Capital International K.K., Capital Group Private Client Services, Inc., and Capital Group Investment Management Private Limited (together with CRMC, the "investment management entities"). CII's divisions of each of the investment management entities collectively provide investment management services under the name "Capital International Investors." CII is deemed to be the beneficial owner of 1,675,351 shares or 4.7% of the 35,328,115 shares believed to be outstanding.</amountBeneficiallyOwned>
        <classPercent>4.7</classPercent>
        <numberOfSharesPersonHas>
          <solePowerOrDirectToVote>1,675,351</solePowerOrDirectToVote>
          <sharedPowerOrDirectToVote>0</sharedPowerOrDirectToVote>
          <solePowerOrDirectToDispose>1,675,351</solePowerOrDirectToDispose>
          <sharedPowerOrDirectToDispose>0</sharedPowerOrDirectToDispose>
        </numberOfSharesPersonHas>
      </item4>
      <item5>
        <classOwnership5PercentOrLess>Y</classOwnership5PercentOrLess>
      </item5>
      <item6>
        <notApplicableFlag>Y</notApplicableFlag>
      </item6>
      <item7>
        <notApplicableFlag>Y</notApplicableFlag>
      </item7>
      <item8>
        <notApplicableFlag>Y</notApplicableFlag>
      </item8>
      <item9>
        <notApplicableFlag>Y</notApplicableFlag>
      </item9>
      <item10>
        <notApplicableFlag>N</notApplicableFlag>
        <certifications>By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.</certifications>
      </item10>
    </items>
    <signatureInformation>
      <reportingPersonName>Capital International Investors</reportingPersonName>
      <signatureDetails>
        <signature>Aaron Espin</signature>
        <title>Senior Vice President</title>
        <date>11/13/2025</date>
      </signatureDetails>
    </signatureInformation>
  </formData>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
