| Abbreviation | Definition |
|---|---|
| ROS | Reed Organ Society |
| RPHS | Republican Party Historical Society |
| RPS | Religion Politics Society |
| RPS | Royal Pharmaceutical Society |
| RPS | Royal Philharmonic Society |
| RPSC | Royal Philatelic Society of Canada |
| RPSE | Royal Physical Society of Edinburgh |
| RPSI | Railway Preservation Society of Ireland |
| RPSL | Royal Philatelic Society of London |
| RPSS | Retinitis Pigmentosa Society Singapore |
| RPSS | Ryukyu Philatelic Specialist Society |
| RRAS | Red Rock Audubon Society |
| RRMAS | Razorback Reef Marine Aquarium Society (Arkansas) |
| RRSS | Regional Residential Services Society |
| RS | Royal Society |
| RS | Royal Society of London |
| RSA | Rhetoric Society of America |
| RSA | Royal Scottish Academy |
| RSA | Royal Society for the Encouragement of Arts, Manufactures and Commerce |
| RSAA | Royal Society for Asian Affairs |