| Reactor Catalysis Research Center | Academic & Science |
| Relational Coordination Research Collaborative | Academic & Science |
| Research Consultants Review Committee | Academic & Science |
| Reston Community Reinvestment Corporation | Business |
| Rosenberg Corporate Research Center | Business |
| Reflective Composition for Rays Concentration | Business |
| Reinforced Concrete Research Council | Business |
| RC2 Corporation | Business |
| Red Canyon Range Camp | Community |
| Resource Center for Roma Communities | Community |
| Redlands Christian Reformed Church | Community |
| River City Residence Club | Community |
| Recovering Community Resource Committee | Community |
| Radical Culture Research Collective | Community |
| Religious Coalition for Reproductive Choice | Community |
| Rutherford County Rescue Crew | Community |
| Rio Colorado Reclamation Committee | Community |
| Regional Council of Rural Counties | Community |
| River City Rock Crawlers | Community |
| Redwood Coast Regional Center | Community |
| Rural Communities Resource Center | Community |
| Rochester Christian Reformed Church | Community |
| Roanoke College Remote Computing | Computing |
| Rocket City Radio Controllers | General |
| Red Cross Red Crescent | General |
| Rate Compatible Repetition Convolutional | General |
| Rain City Rock Camp | General |
| Redwood Caregiver Resource Center | General |
| Rocket City Rock Crawlers | General |
| Registry of Corvette Race Cars | General |
| Richland County Recreation Commission | Governmental |
| Roscommon County Road Commission | Governmental |
| Rural County Representatives of California | Regional |
| Regional Cost Recovery Coordinator | Regional |
| Rose City Rowing Club | Sports |
| River City Rowing Club | Sports |
