| Abbreviation | Definition |
|---|---|
| OHD | Other Health Disabilities |
| OHD | Overhead |
| OHMS | Office of Hearings and Mediation Services |
| OHO | Office of Hearing Officers |
| OHO | One Huge Opportunity |
| OHR | Office of Human Resources |
| OHR | Office of the High Representative |
| OHS | Occupational Health and Safety |
| OHSC | Occupational Health and Safety Committee |
| OI | Obsessive Influence |
| OI | Operation Insanity |
| OI | Outside Influence |
| OIA | Office of Insular Affairs |
| OIA | Office of Integrative Activities |
| OIA | Office of International Affairs |
| OIA | Overseas Investment Act |
| OIC | Office of Independent Counsel |
| OIE | World Organisation for Animal Health United Nations (FAO) |
| OIM | Office of Investment Management |
| OIN | Oversight Information Network |