| Reqfast | Arizona |
| ReqStudio | California |
| ReQuest Ltd | Wisconsin |
| Required Marketing Group, Inc. | |
| RequirementONE | California |
| Res Nova Bio | |
| Resaleworld.com | Florida |
| Rescale | California |
| ReSci | California |
| Rescue Computer Service | New Jersey |
| Rescue Hearing, Inc. | |
| Rescue Marketing, Inc. | |
| Rescue My Gadget | Kansas |
| Rescue Phone, Inc. | Maryland |
| RESCUECOM Corporation | New York |
| RescueTime | |
| Research and Testing Laboratories, LLC | |
| Research Concepts, Inc. | |
| Research Electronics International | Tennessee |
| Research Foundation for The State University of New York | New York |
| Research Into Internet Systems, LLC | Michigan |
| Research Park at Florida Atlantic University | Florida |
| Research Park FAU | Florida |
| Research Software Design | Oregon |
| Research Triangle Park | North Carolina |
| Research.com | |
| ResearchBuz | California |
| ResearchDx | California |
| ResearchFirst, Inc. | Mississippi |
| Researchware, Inc. | Massachusetts |
| ReSec Technologies | New York |
| Reseller Services, Inc. | New Jersey |
| ResellerChoice | New Jersey |
| Resend | California |
| Resero Analytics, Inc. | |
| Reserv, Inc. | |
| Reserva | |
| Reservations Gateway, Inc. | Virginia |
| Reservations.com | |
| ReServe Interactive | California |
| Reservoir Labs | New York |
| Reservoir Neuroscience | California |
| ReShape Lifesciences | California |
| Resident Spark | |
| Residential Control Systems, Inc. | California |
| Resideo Technologies, Inc. | Texas |
| Resilience Code | Colorado |
| Resilience Cyber Insurance Solutions | California |
| Resilient Point, LLC | Maryland |
| Resilient Ventures | North Carolina |