| Abbreviation | Definition |
|---|---|
| OPPM | Operating Policy and Procedure Manual |
| OPPN | Operation Technical Policy and Procedure Notices (NYC) |
| OPRA | Occupational Pensions Regulatory Authority |
| OPRA | Office of Pre-award Research Administration |
| OPRA | Ohio Parks and Recreation Association |
| OPRA | Open Public Records Act |
| OPSB | Office of Personnel Services and Benefits |
| OPSB | Ohio Power Siting Board |
| OPSC | Office of Public School Construction |
| OPSC | Ohio Polymer Strategy Council |
| OPSC | Oregon Plumbing Specialty Code |
| OPSC | Orissa Public Service Commission |
| OPSE | Office of Protocol and Special Events |
| OPSE | Office of Public Service Employment |
| OPSF | Owen-Putnam State Forest |
| OPSP | Open Project and Selection Process |
| OPSTC | Ontario Production Services Tax Credit |
| OPSW | Oregon Plan for Salmon and Watersheds |
| OR | Oregon |
| ORB | Ontario Review Board |