| Attorney Marketing Network | |
| AttorneySync | Illinois |
| AttoTube | California |
| Attract.Click | |
| Attracta, Inc. | Florida |
| Attracting Solutions, LLC | Florida |
| Attraction, LLC | Delaware |
| Attractor Ventures, LLC | Washington |
| Attralus, Inc. | California |
| Attronica | Maryland |
| Attune | Virginia |
| Attune Medical | Illinois |
| Attune Neurosciences, Inc. | |
| Attuned Intelligence | |
| Attuzi Creative, LLC | Florida |
| Attwill Medical Solutions | Wisconsin |
| ATUM | California |
| Aturo Digital | |
| ATW Partners, LLC | |
| Atwix | Illinois |
| ATX Hack for Change | Texas |
| ATX Venture Partners | Texas |
| ATX Web Design | Texas |
| ATX Web Designs | |
| ATXPowerSupplies.com | Louisiana |
| Atyeti, Inc. | New Jersey |
| Atypic | |
| Atypon Systems, Inc. | California |
| aTyr Pharma | |
| AU21 Capital | California |
| Aubrant Digital | |
| Auburn Software Company | Washington |
| Auburn University at Montgomery | Alabama |
| Auburn University Department of Computer Science and Software Engineering | Alabama |
| Auburn University Department of Computer Science Software Engineering | Alabama |
| Auburn University Department of Electrical and Computer Engineering | Alabama |
| Auburn University Department of Mathematics and Statistics | Alabama |
| Auburn University New Venture Accelerator | Alabama |
| Auburn University Quantum Systems | Alabama |
| Aucta Pharma | |
| Auction Edge, Inc. | Washington |
| Auction Systems, Inc. | Colorado |
| Auction, Inc. | Massachusetts |
| AuctionSoftware.com | Texas |
| Auctus Marketing | |
| Auctus Surgical | California |
| Audacious Software | Illinois |
| Audacy, Inc. | |
| Audama Software, Inc. | Oregon |
| Audax Solutions, LLC | Ohio |