| Acronym | Definition |
|---|
| OAR | Oregon Administrative Rules |
| OAR | Office of Air and Radiation |
| OAR | Of A Revolution (band) |
| OAR | Original Aspect Ratio (for movies on DVD) |
| OAR | Office of Oceanic and Atmospheric Research |
| OAR | Office of AIDS Research (National Institutes of Health) |
| OAR | Offender Aid and Restoration |
| OAR | Office of Administrative Rules |
| OAR | Operating After Revocation (law enforcement) |
| OAR | Office of Alumni Relations (various universities) |
| OAR | Ontario Action Researcher (electronic journal) |
| OAR | Opportunities, Alternatives and Resources |
| OAR | Order of Augustinian Recollects (Religious Order) |
| OAR | Office of Aerospace Research |
| OAR | Open-Air Range |
| OAR | Officer Aptitude Rating (Aviation Selection Test Battery) |
| OAR | Online Annual Report |
| OAR | Online Advertising Report |
| OAR | Off-Axis Ratio |
| OAR | Operations Assistance Request |
| OAR | Office of Air Resources |
| OAR | Ocular Albinism, Autosomal Recessive |
| OAR | Optical Application Router (Atoga) |
| OAR | Organizational/Team Achievement Recognition |
| OAR | Organized Avalanche Response |
| OAR | Open Account Relation |
| OAR | Overhead Administration Recovery |
| OAR | Operational Assessment and Readiness |
| OAR | Ordnance Alteration Requirement |
| OAR | Optically Pre-Amplified Receiver (Bellcore) |
| OAR | Order of Agape and Reconciliation |
| OAR | Order Approving Replacement |
| OAR | Operator Access Record (AT&T) |
| OAR | Ohio Amblyope Registry (Columbus, OH) |
| OAR | Operational Analysis & Reporting |
| OAR | Operational Availability and Reliability |
| OAR | Office of Applied Research (various organizations) |
| OAR | Owner's Authorized Representative (various organizations) |
| OAR | Office of Admissions and Records (various schools) |