| Abbreviation | Definition |
|---|---|
| RM | Running Man |
| RMC | Regional Match Course |
| RMD | Rocky Mountain Division |
| RMDA | Rocky Mountain Dart Association |
| RMF | Rocky Mountain Freestyle |
| RMFC | Reggie McKenzie Football Clinic |
| RMFF | Reggie McKenzie Football Foundation |
| RMM | Rocky Mountain Moggers |
| RMP | Racing Motorsports Productions |
| RMPC | Rocky Mountain Paintball Championship |
| RMR | Rocky Mountain Raceway |
| RMS | Race Marque Systems |
| RMTC | Rocky Mountain Tennis Center |
| RN | Real Nimrod |
| RNFA | Royal Navy Football Association |
| RNM | Richard Noblitt Motorsports |
| RNS | Ranking Not Starting |
| RNT | Residual Nitrogen Time (Diving) |
| ROAR | Radio Operated Auto Racing |
| ROAR | Rules Often Are Rewritten |