| ORR | Objective Response Rate
| Others |
| ORR | Obligatory Risk Ratio
| Others |
| ORR | Off Road Racing
| Others |
| ORR | Off Road Radials
| Others |
| ORR | Off Road Register
| Others |
| ORR | Off Road Report
| Others |
| ORR | Office of Rail Regulation
| Others |
| ORR | Office of Rail regulations
| Others |
| ORR | Office of Refugee Resettlement
| Others |
| ORR | Office of Regulatory Reinvention
| Others |
| ORR | Offroad Racing Romania
| Others |
| ORR | Offshore Racing Rule
| Others |
| ORR | Old Rochester Regional
| Others |
| ORR | On-line Resource Room
| Others |
| ORR | One-Way Roadways and Rotaries
| Others |
| ORR | Open Road Racing
| Others |
| ORR | Operations Requirements Review
| Others |
| ORR | Optimal Route Reflection
| Others |
| ORR | Organization of Resident Representatives
| Others |
| ORR | Oriental Rug Review
| Others |
| ORR | Osage Railroad
| Others |
| ORR | Outer Ring Road
| Others |
| ORR | Oxidation-Reduction Reaction
| Others |
| ORR | Oxygen Reduction Reaction
| Others |
| ORR | Yorketown, South Australia, Australia
| Others |