| AllegisCyber | California |
| Allego | |
| Allegro Commodity Mangement | Texas |
| Allegro Consultants, Inc. | California |
| Allegro MicroSystems, Inc. | Massachusetts |
| Allegro Ophthalmics, LLC | California |
| Allegro Software Development Corporation | Massachusetts |
| Allegro.cc | Illinois |
| Allele Biotechnology | |
| Allele Diagnostics | |
| Allelica, Inc. | New York |
| Allen & Gerritsen | |
| Allen Ayler | Oregon |
| Allen Business Machines Co. | Maryland |
| Allen Communication Learning Services | Utah |
| Allen Developers | |
| Allen Holub | California |
| Allen Institute | Washington |
| Allen Institute for Artificial Intelligence | Washington |
| Allen Institute for Cell Science | |
| Allen Interactions | Minnesota |
| Allen University | South Carolina |
| Allen Wayne Ltd | |
| Allendevaux & Company, LLC | Ohio |
| AllerGenis, LLC | Pennsylvania |
| Allevi, Inc. | |
| Alleviant Medical, Inc. | Texas |
| Alleviant Medical, Inc. | |
| Allevion Therapeutics, Inc. | |
| Alley Cat Media | Virginia |
| Alley Interactive, LLC | New York |
| Alley Stoughton | Massachusetts |
| AlleyCorp | New York |
| AlleyWatch, LLC | New York |
| Allez Health, Inc. | |
| Allfax Specialties, Inc. | Louisiana |
| Allfon, LLC | California |
| AllGPTs | |
| Allgress, Inc. | California |
| Alliance Analytics | Illinois |
| Alliance Communications | South Dakota |
| Alliance Computers | Pennsylvania |
| Alliance Enterprises, Inc. | Washington |
| Alliance for Affordable Internet | District of Columbia |
| Alliance for Aging Research | |
| Alliance for Audited Media | Illinois |
| Alliance for Biosecurity | |
| Alliance for Building Better Medicine | |
| Alliance for Open Media | Massachusetts |
| Alliance for Telecommunications Industry Solutions | District of Columbia |