| Artlantis Design Studio | |
| Artmil Design | |
| Artol Consulting, LLC | |
| Artonic | Michigan |
| Artopa, LLC | Maine |
| Artoss, Inc. | |
| Artron BioResearch, Inc. | |
| Arts People | Oregon |
| Artsci Publishing | California |
| Artsnacks, LLC | |
| ArtVersion | Illinois |
| Artwork Conversion Software, Inc. | California |
| Artwork Creative | |
| ArtworkServicesUSA | Maryland |
| Artwurks Unlimited | |
| Aruba | California |
| Arugula Sciences | Texas |
| Aruna Bio | Georgia |
| Arva AI, Inc. | |
| Arvaan Techno-Lab, LLC | |
| Arvada Therapeutics | |
| Arvig Enterprises | Minnesota |
| Arvinas | Connecticut |
| Arvist AI | |
| Arvixe, LLC | California |
| ARVMarketing | |
| Arvo Digital | |
| ARVYS Proteins, Inc. | Connecticut |
| ARX Sciences, Inc. | |
| arXiv.org | New York |
| Arxspan | Massachusetts |
| Arya Boudaie | |
| Arya Health | |
| Aryaka Networks, Inc. | California |
| Aryeo, Inc. | Massachusetts |
| Aryon | |
| Aryosys | California |
| Arytha Biosciences, LLC | California |
| ARYU Advertising | |
| ARZ NxT, LLC | |
| Arzeda | Washington |
| AS Creative Services | |
| AS Designs & Services, LLC | |
| AS-Photonics, LLC | New Mexico |
| AS/SURE Software | North Carolina |
| ASA Automotive Systems, Inc. | New Hampshire |
| ASA Computers, Inc. | California |
| Asage Marketing | |
| Asahi Kasei Corporation | |
| Asahi Spectra USA, Inc. | California |