| Acronym | Definition |
|---|
| RRI | Radio Romania International |
| RRI | Raman Research Institute |
| RRI | Reverse Route Injection (routing process) |
| RRI | Radio Republik Indonesia (Indonesian national radio station; est. 1945) |
| RRI | Resource Renewal Institute |
| RRI | Robarts Research Institute |
| RRI | Riverside Research Institute |
| RRI | Renal Research Institute (USA) |
| RRI | Research Reactor Institute |
| RRI | Régime de Retraite Individuel (French: Individual Pension Plan; Canada) |
| RRI | Rainforest Rescue International |
| RRI | Route Relay Interlocking (railway signaling) |
| RRI | Rhein Ruhr International (German engineering company) |
| RRI | Rick Ross Institute (cults) |
| RRI | Regional Return Initiative (now part of MARRI) |
| RRI | Response Resource Inventory |
| RRI | Response to Request for Information |
| RRI | Recognition Research, Inc. (Blacksburg, VA; est. 1989) |
| RRI | Race Relations Institute (Fisk University; Nashville, TN) |
| RRI | Resource Reservation Interval |
| RRI | Reverse Rate Indication |
| RRI | Range Response Improvement (marksmanship) |
| RRI | Railroad Inspections (VRE) |
| RRI | Recognition Research International |
| RRI | Ready for Roll-out and Implementation |
| RRI | Remote Radio Interface |
| RRI | Risk Reduction Interval |
| RRI | Ryan Research International (research and publishing organization; Chico, CA) |
| RRI | Rights and Resources Initiative |
| RRI | Rotman Research Institute |
| RRI | Residential Recycling Initiative |