| Acronym | Definition |
|---|
| ORR | Office of Rail Regulation (UK government; formerly Office of the Rail Regulator) |
| ORR | Outer Ring Road (Hyderabad, India) |
| ORR | Office of Refugee Resettlement (HHS) |
| ORR | Oak Ridge Reservation (Tennessee) |
| ORR | Overall Response Rate (medical treatment) |
| ORR | Office of Response and Restoration (NOAA) |
| ORR | Old Rochester Regional (Massachusetts) |
| ORR | Objective Response Rate |
| ORR | Open Records Request (various locations) |
| ORR | Office of the Rail Regulator (UK government; now Office of Rail Regulation) |
| ORR | Operational Readiness Review |
| ORR | Oxygen Reduction Reaction (energy science) |
| ORR | Online Research Resource (Illinois) |
| ORR | Office of Regulation Review (Australia) |
| ORR | Ordered Round Robin |
| ORR | Obligor Risk Rating |
| ORR | Orroral Valley, Australia (GSTDN tracking station) |
| ORR | Off-The-Road Radial Tire |
| ORR | Operational Readiness Report |
| ORR | Operator Response Required |
| ORR | Operational Replacement Radar |