| RAD Security | |
| RAD Software | Florida |
| RAD Websites | |
| Radancy | |
| RADAR | New York |
| Radar Labs, Inc. | |
| Radar Systems Technology, Inc. | California |
| Radar, Inc. | Washington |
| Radella Pharmaceuticals, LLC | |
| Radeus Labs, Inc. | California |
| Radford University | Virginia |
| RADHA | |
| Radial Analytics, Inc. | |
| Radial Solutions | Ohio |
| RadialSpark | Arizona |
| Radian Aerospace | Washington |
| Radiance Biopharma, Inc. | |
| Radiance Technologies, Inc. | Alabama |
| Radiance Therapeutics, Inc. | |
| Radianse, Inc. | Massachusetts |
| Radiansys, Inc. | |
| Radiant Earth | |
| Radiant Infotech | Maryland |
| Radiant Logic, Inc. | California |
| Radiant RFID | Texas |
| Radiant Security, Inc. | |
| Radiant Vision Systems, LLC | Washington |
| Radiant Web Design | |
| RadiantGraph | |
| RadiaSoft, LLC | Colorado |
| Radical | |
| Radical AI Podcast | |
| Radical AI, Inc. | |
| Radical Answers | Alabama |
| Radical Blue Gaming | Nevada |
| Radical Media | |
| RADiCAL Solutions, Inc. | |
| Radical Webs, Inc. | |
| Radicalloop, Inc. | |
| Radicle Growth | |
| Radicle Science | |
| Radicom Research, Inc. | California |
| Radio Communications Management, Inc. | Maine |
| Radio Network, Inc. | California |
| Radio One | Florida |
| Radio Pro Shop | Pennsylvania |
| Radio Resource, Inc. | Colorado |
| Radio Waves, Inc. | Massachusetts |
| Radio Workflow, Inc. | |
| RadioLabs International, Inc. | North Carolina |