| Area 17 | New York |
| Area-Wide Technologies | Illinois |
| Area52 Hosting, LLC | Vermont |
| AreaBeats, LLC | |
| Arealink | Indiana |
| Arecont Vision, LLC | California |
| Arena Analytics, Inc. | Maryland |
| Arena Growth Partners | Texas |
| Arena Technologies, Inc. | |
| ArenaNet, LLC | Washington |
| ArenaSoft, LLC | New York |
| Ares Capital Corporation | Georgia |
| ARES Corporation | California |
| Ares Management Corporation | California |
| Aretec, Inc. | |
| Aretech, LLC | |
| Areteia Therapeutics, Inc. | |
| Areterna, LLC | |
| Arevo Capital, LLC | Pennsylvania |
| Arevon Energy, Inc. | |
| Arex Life Sciences, LLC | Massachusetts |
| ARF Services | |
| ARG, Inc. | |
| Argano | Texas |
| ArganoCSS International, Inc. | South Carolina |
| ArganoInterRel Consulting | Texas |
| Argecy Computer Corporation | Michigan |
| Argent Media | |
| ArgenTag Corporation | |
| Argentum Corporation | Washington |
| Argentum Group | New York |
| Argis Solutions, Inc. | Colorado |
| Argo Networks, Inc. | Kentucky |
| Argo SE, Inc. | Illinois |
| ArgoCTS | Washington |
| Argon AI | |
| Argon Blue | California |
| Argon Corporation | Georgia |
| Argon Hosting | Florida |
| Argon Medical Devices, Inc. | Texas |
| Argon Technology Corporation | Nevada |
| Argonaut | |
| Argonaut Manufacturing Services | California |
| Argonne National Laboratory | Illinois |
| Argonne National Laboratory - Mathematics and Computer Science Division | Illinois |
| Argonteq | |
| Argos Capital Partners, LLC | Missouri |
| Argos InfoTech | Texas |
| Argos Software | California |
| Argos Systems, Inc. | New Hampshire |