| Abbreviation | Definition |
|---|---|
| OEG | Ohio Energy Gateway |
| OEPAF | Odessa Emergency Providers Achievement Fund |
| OEU | Operation Eyesight Universal |
| OFA | Organizing For America |
| OFA | Orphan Foundation of America |
| OFA | Orthopedic Foundation of America |
| OFA | Osteochondrosis Foundation for Animals |
| OFAR | Organization For Autism Research |
| OFC | Ontario Fitness Council (Canada) |
| OFCP | Ontario Federation for Cerebral Palsy |
| OFE | Oklahoma Foundation for Excellence |
| OFFICIAL | Ordinary Folks For Immediate Currency Information And Legislation |
| OFG | Ontario Flower Growers Co-op |
| OFI | Orangutan Foundation International |
| OFI | Ornamental Fish International |
| OFK | Optics For Kids |
| OFO | Ontario Field Ornithilogists |
| OFO | Oregon Field Ornithologists |
| OFPA | Oregon Foster Parent Association |
| OFPA | Ozark Food Processors Association |