| Acronym | Definition |
|---|
| RIR | Rock in Rio (rock music festival) |
| RIR | Richmond International Raceway |
| RIR | Regional Internet Registry |
| RIR | Rhode Island Red (chicken) |
| RIR | Release Initiation Review |
| RIR | Renault Industrie Roumanie |
| RIR | Rosebud Indian Reservation (South Dakota) |
| RIR | Royal Irish Regiment |
| RIR | Reduction In Recruitment |
| RIR | Research in Review (Pennsylvania Department of Corrections) |
| RIR | Recordable Incident Rate (occupational safety statistic) |
| RIR | Regulatory Impact Review (fishing) |
| RIR | Recordable Injury Rate (workplace injuries) |
| RIR | Royal Irish Rifles |
| RIR | Reference Intensity Ratio |
| RIR | Room Impulse Response (acoustics) |
| RIR | Remedial Investigation Report |
| RIR | Responses to Information Requests |
| RIR | Railway Interoperability Regulations (UK) |
| RIR | Roth Investor Relations, Inc. (Manalapan, NJ) |
| RIR | Range Instrumentation Radar |
| RIR | Receiving Inspection Report |
| RIR | Réseau Inter-Régional (French: Inter-Regional Network) |
| RIR | Repatriation Information Report |
| RIR | Relative Importance Rating (customer service issues) |
| RIR | Refund Intercept Request |
| RIR | Risk Identification Report |
| RIR | Rights and Interest Records |
| RIR | Reduction in Recordable |
| RIR | Rapid Information Retrieval |
| RIR | Residual Impairment Ratio |
| RIR | Readiness Improvement Review |
| RIR | Reportable Item Report (US NASA) |
| RIR | Rapid Incident Response |