| Abbreviation | Definition |
|---|---|
| OATS | Oral Anecdotes And Testamentary Stories |
| OBA | Oxygen Breathing Apparatus |
| OBJ | Objection |
| OBRA | Omnibus Budget Reconciliation Act of 1981 |
| OBS | Oriental Blank Stare |
| OBT | Orgain, Bell, Tucker, L. L. P. |
| OBTS | Offender Based Tracking System |
| OBV | OBVious |
| OC | Organized Clan |
| OC | Organized Crime |
| OCA | Originating Case Agency Number |
| OCAA | Omnibus Consolidated Appropriations Act of 1997, P.L. 104-368 |
| OCAA | Orange County Attorneys Association |
| OCAVI | Observatorio Centroamericano sobre Violencia (The Central American Observatory on Violence) |
| OCB | Organized Crime Bureau |
| OCCB | Organized Crime Control Bureau |
| OCIE | Observe Connect Interpret And Evaluate |
| OCR | One Critical Record |
| OCR | Open Court Reading |
| OCSH | Office of Child Support Hearings |