Exhibit 21.1

SUBSIDIARIES OF ABM INDUSTRIES INCORPORATED

The following is a list of subsidiaries of the company as of October 31, 2022, omitting subsidiaries which, considered in the aggregate, would not constitute a significant subsidiary.

Company		Where Incorporated or Organized
ABM INDUSTRIES INCORPORATED		Delaware
(*)	ABM Aviation, Inc.	Georgia
	ABM International Limited	Bermuda
	ABM International (Holdings) Ltd	England
	ABM Aviation UK Limited	England
	OFJ Connections	England
	OFJ Airlinks Limited	England
	ABM Group UK Limited	England
	ABM Facility Services UK Limited	England
	BRBIBR Limited	England
	ABM Critical Solutions Limited	England
	ABM International (Holdings) B.V.	Holland
	ABM Onsite Services - Canada ULC	Canada
	Westway Services Holdings (2014) Ltd.	England
	Westway Services Holdings (2010) Ltd.	England
	ABM Technical Solutions Limited	England
	Maybin Support Services (Ireland) Limited	N. Ireland
	Momentum Support Limited	Ireland
	Momentum Property Support Services Ltd.	N. Ireland
	ABM Building & Energy Solutions, LLC	Delaware
	ABM Building Services, LLC	Delaware
	ABM Building Solutions, LLC	Delaware
	ABM Electrical & Lighting Services, LLC	Delaware
	ABM Electrical & Lighting Solutions, Inc.	Delaware
	ABM Electrical Power Services, LLC	Delaware
	ABM Electrical Power Solutions, LLC	Delaware
	ABM Facility Support Services, LLC	Delaware
	RenewEnergy Solutions, LLC	Delaware
	ABM Canada Power Services LTD	Canada
	ABM Building & Energy Services, LLC	Delaware
	ABM eMobility, LLC	Delaware
	ABM eMobility USA, LLC	Delaware
	ABM Franchising Group, LLC	Delaware
	ABM General Services, Inc.	Delaware
	ABM Healthcare Support Services, Inc.	Michigan
	ABM Industrial Services, Inc.	Delaware
	ABM Industry Groups, LLC	Delaware
	Crown Building Maintenance Co.	California
	CBM MGMT LLC	California
	Crown Energy Services, Inc.	California
	Able Advantage Acquisition, Inc.	Delaware

AES MGMT, LLC	California
AbleServe Management Company	California
ABM Texas General Services, Inc.	Delaware
Grade Sub Two, LLC	Delaware
GCA Services Group, Inc.	Delaware
Associated Facility Management, LLC	Nevada
GCA Cleaning Specialties, LP	Texas
GCA Services Group Mountain States, LP	Texas
GCA Services Group of Texas, LP	Texas
Associated Facility Ventures, LLC	Nevada
GCA Education Services, Inc.	Tennessee
GCA Education Services Central States, Inc.	Illinois
GCA Education Services of New England, Inc.	Delaware
GCA K12 Education Services, Inc.	Texas
GCA Nuclear Facility Services, Inc.	Texas
GCA Production Services, Inc.	Delaware
GCA Services Group of California, Inc.	California
GCA Services Group of Colorado, Inc.	Colorado
GCA Services Group of North Carolina, Inc.	North Carolina
GCA Services Group of Northwestern States, Inc.	Washington
GCA Staffing Services, Inc.	Delaware
National Building Maintenance Corp.	Delaware
IFM Assurance Company	New York
RavenVolt, Inc.	Georgia
Linc International, Inc.	Delaware
Linc Facility Services Iraq LLC	Delaware
Wassl Al-Iraq Project Services & General Contracting LLPC	Iraq
Linc Facility Services ME, LLC	Delaware
Linc Facility Services Saudi Arabia, LLC	Saudi Arabia

*Subsidiaryrelationship to Company or to subsidiary parents shown by progressive indentation.