| Abbreviation | Definition |
|---|---|
| OT | Out Of Town |
| OTA | Office of Tax Analysis |
| OTAO | Oklahoma - Texas Area Office |
| OTB | Ontario Trillium Benefit |
| OTC | Oklahoma Tax Commission |
| OTCD | Oasis Tax Collection and Distribution system |
| OTDB | Old Town Development Board |
| OTF | Ontario Trillium Foundation |
| OTH | One Tree Hill |
| OTRS | Oklahoma Teachers Retirement System |
| OTW | On The Waterfront |
| OUA | Office of Urban Affairs |
| OUC | Ontario Underwater Council |
| OUC | Orlando Utilities Commission |
| OVA | Office of Veterans Affairs |
| OVA | Office of Victim Assistance |
| OVP | Office of Voluntary Programs |
| OVR | Office of Vocational Rehabilitation |
| OW | Ontario Works |
| OWA | Office of the Worker Adviser |