| ARMON Technologies, LLC | Massachusetts |
| Armonica Technologies, Inc. | California |
| Armonk Computer Solutions | New York |
| Armor Defense, Inc. | Texas |
| Armor Interactive | North Dakota |
| Armor Medical, Inc. | |
| Armor Systems & Security, Inc. | Florida |
| ArmorCode, Inc. | California |
| ArmorSuit | California |
| Armory | California |
| ARMS Business & Technology Solutions | Nevada |
| ARMS Software | Virginia |
| Armstrong Agency | |
| Armstrong Communication Systems, Inc. | New York |
| Armstrong Robotics, Inc. | |
| Armstrong Telecom | New York |
| Armus | California |
| ARNA Genomics US, Inc. | |
| Arnab Nandi | Ohio |
| Arnatar Therapeutics | |
| ArNetEx | Arkansas |
| Arney Computer Systems | Texas |
| Arnica, Inc. | Georgia |
| Arnima Design, Inc. | Florida |
| Arnold Magnetics Corporation | California |
| Arnold Worldwide | |
| Aro Biotherapeutics | |
| AROG Pharmaceuticals | |
| Arogo.Net | California |
| ArohaTech IT Services (P) Ltd | California |
| Arondite | |
| Aronetics | Ohio |
| Aronfield | |
| Aronora, Inc. | Oregon |
| Aroopa, Inc. | New Jersey |
| Aroostook Savings & Loan | |
| Arosys | |
| Around Houston | Texas |
| ARP Networks, Inc. | California |
| Arpeggio | |
| Arpeggio Software, LLC | Georgia |
| Arphie, Inc. | |
| Arpio | North Carolina |
| Arq | Massachusetts |
| ARQ Genetics | |
| Arrakis Therapeutics | |
| Array | |
| Array Digital | |
| Array Networks, Inc. | California |
| Array Software | Massachusetts |