| ACT Robots | Connecticut |
| ACT USA / Sheldon Networks, Inc. | California |
| Act!, LLC | Arizona |
| Act-On Software, Inc. | Oregon |
| Acta Design | California |
| ACTA Laboratories, Inc. | California |
| Actalent, Inc. | Maryland |
| ActBlue | Massachusetts |
| Actelis Networks, Inc. | California |
| Actian Corporation | California |
| Actify | California |
| Actify Media, LLC | |
| Actinium Pharmaceuticals, Inc. | New York |
| Actio Biosciences, Inc. | California |
| Action Communications | |
| Action Communications, Inc. | Arizona |
| Action Computer and Audio Visual, LLC | Texas |
| Action Computers | Colorado |
| ACTION Innovation Network | Massachusetts |
| Action Web Host | Arizona |
| Action1 Corporation | Texas |
| Actiondesk | California |
| ActioNet, Inc. | Virginia |
| Actionfigure | District of Columbia |
| ActionIQ | New York |
| Actionstep Software Ltd | Virginia |
| Actiontec Electronics, Inc. | California |
| ActionTRAK, LLC | Utah |
| ActionWare | California |
| ActionXL‚ LLC | New York |
| Actipro Software, LLC | Ohio |
| ACTIS Computer | Arizona |
| Actisys Corporation | California |
| Activ Surgical, Inc. | Massachusetts |
| Activ Technologies, Inc. | Georgia |
| Activate | New York |
| Activate Global, Inc. | |
| Activate Learning | |
| Activated Communications | California |
| Activated Insights | |
| Activation Capital | Virginia |
| Active Capital | Texas |
| Active Collab, LLC | Virginia |
| Active Data Systems | South Dakota |
| Active Data, Inc. | Pennsylvania |
| Active Ennovations | California |
| Active Impact | Texas |
| Active Internet Marketing | Michigan |
| Active IT Design, LLC | South Carolina |
| Active Layer Parametrics, Inc. | |