| Ad Peeps | North Carolina |
| Ad Results Media | |
| Ad Valorem Records, Inc. | |
| Ad Ventures Design & Marketing | Arizona |
| Ad Vice Marketing | |
| Ad Victorem | |
| Ad Wizards | Texas |
| Ad-Apt | |
| Ad-Mail, Inc. | Oregon |
| Ad-Tech Medical Instrument Corporation | Wisconsin |
| Ad-Vectors Biotech, LLC | |
| Ad.com Interactive Media, Inc. | |
| AD/Solutions Group, Inc. | Illinois |
| AD60, Inc. | New York |
| Ada Conformity Assessment Authority | Wisconsin |
| Ada Developers Academy | Washington |
| ADA Forsyth Institute | |
| ADA Site Compliance | |
| ADA, Inc. | |
| Adacel Technologies Ltd | Florida |
| Adachi Computech Solutions | |
| AdaCore | New York |
| AdAction | Colorado |
| Adaera, LLC | Pennsylvania |
| Adafruit | New York |
| Adafruit Industries | |
| Adage | |
| Adage Design Technologies, LLC | |
| Adage Technologies | Illinois |
| Adagene | California |
| Adager Corporation | Idaho |
| Adagio Medical, Inc. | California |
| Adagio Tech, LLC | Texas |
| Adalo, Inc. | Missouri |
| Adam Auton | California |
| Adam Enfroy Ventures, LLC | |
| Adam Fard Studio | New York |
| Adam Fisher-Cox | New York |
| Adam Technologies, Inc. | New Jersey |
| Adam Weston | California |
| Adam's Electronics | California |
| Adamant Online Store | Ohio |
| Adamas Optics, LLC | Idaho |
| Adams & Knight, Inc. | |
| Adams Capital Management, Inc. | |
| Adams Clinical | |
| Adams Consulting Group, Inc. | Georgia |
| Adams Digital Services | |
| Adams State University | Colorado |
| Adams Telephone Co-Operative | Illinois |