| Abbreviation | Definition |
|---|---|
| ODP | Olympic Development Program |
| ODSL | Old Dominion Soccer League |
| ODT | Omni Directional Treadmill |
| OEC | Orange Empire Conference |
| OEF | Oklahoma Earthbike Fanatics |
| OEF | Ontario Equestrian Federation |
| OEG | Outdoor Equipment Guide |
| OEJ | One- Eyed Jack |
| OESD | Open-Ended Straight Draw |
| OF | Outfield |
| OFA | One For All |
| OFAH | Ontario Federation of Anglers and Hunters |
| OFB | Organized Filipino Basketball |
| OFC | Oceania Football Confederation |
| OFC | Ochiba Fight Center |
| OFC | Ontario Fitness Council |
| OFCC | Olympia Fields Country Club |
| OFH | Opposite Field Hit |
| OFI | Omilos Filathlon Irakliou (Greek soccer team) |
| OFL | Official Football League (Fantasy Football) |