Exhibit 21.1
LIST OF SUBSIDIARIES OF THE REGISTRANT
| Subsidiary |
Registered Jurisdiction | |
| 3D/lnternational, Inc. | Texas | |
| Argotek, Inc. | Virginia | |
| Barton-Aschman Associates, Inc. of Ohio | Ohio | |
| Bonifica S.P.A. | Italy | |
| Bright Star For Engineering Services LLC | Iraq, Republic of | |
| BSX Parsons LLC | Delaware | |
| Centerra-Parsons Pacific, LLC | Florida | |
| Chas. T. Main of Louisiana, Inc. | Louisiana | |
| Chas. T. Main, Inc. | Massachusetts | |
| Checkmark Vehicle Safety Services, Inc. | Delaware | |
| De Leuw, Cather & Company | Illinois | |
| De Leuw, Cather International Inc. | Illinois | |
| De Leuw, Cather International Limited | Delaware | |
| Delcan Corporation | Illinois | |
| Delcan Ltée | Quebec | |
| Delcan Professional Corporation | Michigan | |
| Delcan Technologies, Inc. | Georgia | |
| Delcather Limited Inc. | Illinois | |
| DZSP 21 LLC | Delaware | |
| EXi Parsons Telecom Inc. | Delaware | |
| EXi Parsons Telecom LLC | Delaware | |
| Finley McNary Engineers, Inc. | Florida | |
| Fourth Dimension Engineering LLC | Delaware | |
| Global Response Services LLC | Delaware | |
| H . E. Hennigh, Inc. | Georgia | |
| Holding S.r.L. | Italy | |
| International Aviation Consultants, L.L.C. | Georgia | |
| KP Leasing Company | Nebraska | |
| Nateng Technology Group, Inc. | Illinois | |
| OGS Holdings, Inc. | Delaware | |
| OGSystems, LLC | Virginia | |
| PARCAN, Inc. | Delaware | |
| Parfinco, Inc. | California | |
| Parsons Advanced Technologies Inc. | Delaware | |
| Parsons Architectural Services of Illinois Inc. | Illinois | |
| Parsons Architecture of Florida Inc. | Florida | |
| Parsons Architecture of New Jersey P.C. | New Jersey | |
| Parsons China Inc. | Nevada | |
| Parsons Commercial Services Inc. | California | |
| Parsons Construction Craft Services Inc. | Texas | |
| Parsons Construction Group Inc. | Delaware | |
| Parsons Constructors & Fabricators Inc. | Delaware | |
| Parsons Constructors Inc. | Delaware | |
| Parsons Corporation | Delaware | |
| Parsons CTMain Projetos de lnfraestrutura Sociedade Simples Ltda. | Brazil | |
| Parsons Delcan Inc. | Delaware | |
| Parsons Engineering Inc. of Michigan | Michigan | |
| Parsons Engineering Limited | Cork | |
| Parsons Engineering of New York, Inc. | New York | |
| Parsons Engineering Science International, Inc. | Delaware | |
| Parsons Engineering Science, Inc. | California | |
| Parsons Enterprises, Inc. | Delaware | |
| Parsons Environment & Infrastructure Group Inc. | Delaware | |
| Parsons Federal Construction Inc. | California | |
| Parsons Global Services, Ltd. | Cayman Islands (B.W.I.) | |
| Parsons Government Services Inc. | Nevada | |
| Parsons Government Services International Inc. | Delaware | |
| Parsons Government Support Services Inc. | Texas | |
| Parsons Group International Limited | United Kingdom | |
| Parsons Hanford Fabricators Inc. | Washington | |
| Parsons Inc. | Federally Chartered | |
| Parsons Infrastructure & Technology Group Inc. of Ohio | Ohio | |
| Parsons Infrastructure & Technology Group of Illinois P.C. | Illinois | |
| Parsons Infrastructure & Technology Group of Michigan Inc. | Nevada | |
| Parsons Infrastructure & Technology Group of New York Inc. | New York | |
| Parsons Inspection & Maintenance Corporation | Delaware | |
| Parsons International Limited | Delaware | |
| Parsons International Limited | Nevada | |
| Parsons Investments Corp. | Delaware | |
| Parsons Italia S.r.L. | Italy | |
| Parsons Main of New York, Inc. | New York | |
| Parsons Main, Inc. | Massachusetts | |
| Parsons Middle East Corporation | Nevada | |
| Parsons Middle East Ltd. | Delaware | |
| Parsons of North Carolina Inc. | North Carolina | |
| Parsons of Puerto Rico Professional Engineers, P.S.C. | Puerto Rico | |
| Parsons Overseas Company | Nevada | |
| Parsons Overseas Limited Inc. | Delaware | |
| Parsons PATCO Inc. | Delaware | |
| Parsons Professional Corporation | District of Columbia | |
| Parsons Professional Services Inc. | Ontario | |
| Parsons Project Services, Inc. | California | |
| Parsons RCI Inc. | Washington | |
| Parsons S.I.P. Inc. | Delaware | |
| Parsons Savannah Construction Company | South Carolina | |
| Parsons Savannah Services Company | Delaware | |
| Parsons Secure Solutions Inc. | Virginia | |
| Parsons Services Company | Texas | |
| Parsons SGTP GP Holdings Inc. | Ontario | |
| Parsons Technical Services Inc. | Delaware | |
| Parsons Technical Services International Inc. | Texas | |
| Parsons Technical Support Inc. | Delaware | |
| Parsons Technologies, LLC | Delaware | |
| Parsons Telecommunication Services Inc. | Delaware | |
| Parsons Transportation Architectural Services LLC | Delaware | |
| Parsons Transportation Concessionaires LLC | Delaware | |
| Parsons Transportation Group Inc. | Illinois | |
| Parsons Transportation Group Inc. of Michigan | Michigan | |
| Parsons Transportation Group Inc. of Virginia | Virginia | |
| Parsons Transportation Group of New York, Inc. | New York | |
| Parsons Transportation Group, Professional Corporation | District of Columbia | |
| Parsons Water & Infrastructure Inc. | Delaware | |
| Parsons Water Resources, Inc. | California | |
| Parsons-Granite LLC | Delaware | |
| Parsons-Jurden International Corporation | Nevada | |
| Parsons-Versar LLC | Delaware | |
| Partnership for Temporary Housing LLC | Delaware | |
| Polaris Alpha Advanced Systems, Inc. | Virginia | |
| Polaris Alpha Cyber and Sigint, LLC | Delaware | |
| Polaris Alpha Cyber Technologies, LLC | Delaware | |
| Polaris Alpha Equity Holdings, LLC | Delaware | |
| Polaris Alpha Holdings Parent, LLC | Delaware | |
| Polaris Alpha, LLC | Delaware | |
| PTG Construction Services Company | Delaware | |
| PTSI Managed Services Inc. | California | |
| Research and Development Solutions, LLC | Delaware | |
| RMP Infrastructure Holdings Inc. | Ontario | |
| S&P Geology Services P.C. | New York | |
| S.I.P. Engineering, Inc. | Delaware | |
| S.I.P., Inc . | Delaware | |
| SGTP Highway Bypass GP Inc. | Saskatchewan | |
| SGTP Highway Bypass Limited Partnership | Saskatchewan | |
| Solidyn Solutions, LLC | Delaware | |
| Steinman Boynton Gronquist & Birdsall | New York | |
| Steinman Boynton Gronquist & Birdsall Inc. | New Jersey | |
| Steinman Inc. | New York | |
| T. J. Cross Engineers, Inc. | California | |
| The C. T. Main Corporation | Massachusetts | |
| The Ralph M. Parsons Company | Nevada | |
| Wholesale Supply Co., Inc. | Nevada | |
| Williams Electric Co., Inc. | Florida | |