| Abbreviation | Definition |
|---|---|
| ODA | Ontarians with Disabilities Act |
| ODAA | Oklahoma District Attorneys' Association |
| ODAA | Oregon District Attorney's Association |
| ODARA | Ontario Domestic Assault Risk Assessment |
| ODBA | Old Dominion Bar Association |
| ODbL | Open Data Commons Open Database License |
| ODD | Oppositional Defiant Disorder |
| ODESSA | Open Digital Evidence Search And Seizure Architecture |
| OFA | Order for Arrest |
| OFC | Operation First Class |
| OFM | One False Move |
| OFT | Operation Freedom Trip |
| OFWG | Odd Future Wolf Gang |
| OGC | Office of General Counsel |
| OGK | Original Gangsta Killas (gang, operated within the City of Albany) |
| OHIM | Office for Harmonization in the Internal Market |
| OIC | Offer In Compromise |
| OINL | Obedience Is Not Legalism |
| OJ | Obstruction of Justice |
| OJ | Orange Jumpsuit |