Exhibit 21.1

Air Transport Services Group, Inc.

List of Significant Subsidiaries

December 31, 2020

1.ABX Air, Inc., a Delaware Corporation

2.Airborne Global Solutions, Inc., a Delaware Corporation

3.Airborne Maintenance and Engineering Services, Inc., a Delaware Corporation

4.Air Transport International, Inc., a Delaware Corporation

5.Air Transport International Limited Liability Company, a Nevada Limited Liability Company

6.AMES Material Services, Inc., an Ohio Corporation

7.Cargo Aircraft Management, Inc., a Florida Corporation

8.LGSTX Cargo Services, Inc., an Delaware Corporation

9.LGSTX Services, Inc., a Delaware Corporation

10.Pemco World Air Services Inc., a Delaware Corporation

11.ATSG West Leasing Limited, an Irish Limited Company

12.Omni Air International, LLC, a Nevada Limited Liability Company