| 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 |