| Acronym | Definition |
|---|
| ROI | Return on Investment |
| ROI | Region of Interest |
| ROI | Republic Of Ireland |
| ROI | Return of Investment |
| ROI | Release of Information (hospitals/patients) |
| ROI | Risk of Infection (diagnosis) |
| ROI | Report on Industry |
| ROI | Report of Inspection (various locations) |
| ROI | Rate of Interest |
| ROI | Règlement d'Ordre Intérieur (French: Internal Policy and Procedures; Belgium) |
| ROI | Rdma over Internet |
| ROI | Ring of Illusion (gaming tournament) |
| ROI | RDMA (Remote Direct Memory Access) Over Internet |
| ROI | Report Of Investigation |
| ROI | Reactive Oxygen Intermediate |
| ROI | Registration of Interest |
| ROI | Royal Institute of Oil Painters (UK) |
| ROI | Radius Of Influence |
| ROI | RAM Optical Instrumentation |
| ROI | Rules of Interaction (gaming) |
| ROI | Rock of Israel |
| ROI | Risk of Incarceration |
| ROI | Record of Invention |
| ROI | Return on Integrity (finance) |
| ROI | Realm of Influence (band) |
| ROI | Rhino Outdoor International |
| ROI | Report On Investigation |
| ROI | Rural Ontario Institute (Canada) |
| ROI | Remote Operator Interface |
| ROI | Realm of Insanity (gaming clan) |
| ROI | Read Only Information |
| ROI | Replacement of Obsolete Items |
| ROI | Rovaniemi, Finland - Rovaniemi (Airport Code) |
| ROI | Range Operating Instruction |
| ROI | Radiological Operating Instructions |
| ROI | Rhythm Optimized Integration |
| ROI | Route of Ingress |
| ROI | Residue of Ignition |