| Abbreviation | Definition |
|---|---|
| OLC | Office of Legal Counsel |
| OLMS | Office of Labor Management Standards |
| OLP | Office of Legal Policy |
| OLPA | Office of Legislative Policy and Analysis |
| OLPA | Olmsted Linear Park Alliance |
| OLQ | Other Living Quarters |
| OLS | Organizational Leadership Supervision |
| OM | One Mind |
| OM | Operations and Maintenance |
| OMB | Official Message Board |
| OMBTEA | Office of Management and Budget Target Employment Area |
| OMG | Obama Must Go! |
| OMH | Office of Men's Health |
| OMH | Office of Mental Health |
| OMH | Office of Minority Health |
| OMH | Office of Multicultural Health |
| OML | Oil Mining Licence |
| OMM | Offshore Minerals Management Program |
| OMM | On the Macedonian Matter |
| OMNI | Oppose Militancy, Neutralize Invasion |