| Abbreviation | Definition |
|---|---|
| OFS | Oakland Family Services |
| OFS | Ocean Futures Society |
| OFT | Office of Fair Trading |
| OFT | Ontario Farmland Trust |
| OFTA | Outreach For The Animals |
| OG | The Ornithology Group |
| OGA | Ohio Glass Association |
| OGF | One Global Family |
| OGF | Open Gaming Foundation |
| OGT | Orphan Grain Train |
| OH | Ozone House |
| OHB | Operation HeartBeat |
| OHC | Ontario Health Coalition |
| OHE | Office of Health Economics |
| OHEA | Ohio Humane Education Association |
| OHF | One Human Family |
| OHF | Open Hearth Foundation |
| OHF | Open House Financial |
| OHF | Oregon Health Forum |
| OHF | Oxalosis and Hyperoxaluria Foundation |