| Abbreviation | Definition |
|---|---|
| READ | Reading Education Assistance Dogs |
| REEF | Reef Environmental Education Foundation |
| REFAHAID | Relief Empowerment Fund to Advance Humanitarian Assistance Integrated Development |
| REFAHAID | Relief & Empowerment Fund to Advance Humanitarian Assistance & Integrated Development |
| REMSA | Railway Engineering-Maintenance Suppliers Association |
| REPA | Retired Eastern Pilots Association |
| REPG | Race and Equity in Philanthropy Group |
| REPS | Reaching Everyone Preventing Suicide |
| RESCUE | Response for Emergency Situation & Corps for Unpredictable Events |
| RESULTS | Responsibility For Ending Starvation Using Lobbying Trimtabbing And Support |
| ReWA | Refugee Women's Alliance |
| RFA | RainForest Alliance |
| RFA | Religious Freedom Action |
| RFA | Romantic Fireside Association |
| RFAF | Religious Freedom Action Fund |
| RFB&D | Recording for the Blind and Dyslexic |
| RFBD | Reading For The Blind And Dyslexic |
| RFBD | Recording for the Blind and Dyslexic |
| RFD | Royal Flying Doctor |
| RFE | Rotary Fellowship Exchange |