| Abbreviation | Definition |
|---|---|
| RMTC | Racing Medication and Testing Consortium |
| RMTC | Racing Medication Testing Consortium |
| RNA | Reserve Not Announced |
| ROA | Racehorse Owners Association |
| ROAN | Racehorse Outplacement Assistance Network |
| ROAP | Racing Officials Accreditation Program |
| ROAR | Radio-Operated Auto Racing |
| RODS | Racing for Orphans with Down Syndrome |
| ROOTT | Rocking out on the Terrace |
| ROR | Retraining of Racehorses |
| ROR | Rookie Of the Race |
| RORC | Royal Ocean Racing Club |
| ROS | Race Online Series |
| ROTA | Race On The Agenda |
| ROTB | Race on the Base |
| RP | Racing Post |
| RPAT | Racing Penalties Appeal Tribunal |
| RPC | Racing Power Company |
| RPD | Racing Product Division |
| RPM | Race Performance and Modification |