| Abbreviation | Definition |
|---|---|
| OLR | On-Line Residential |
| OLR | OnlineRock Music Store |
| OLRC | Old Lyric Repertory Company |
| OLRT | On Line Radio Trader |
| OLS | Oosterum Loudspeaker Systems |
| OLW | OnlineWorld.com, L. L. C. |
| OLX | Off Line Express |
| OLY | Olympian |
| OM | Oel Motor |
| OM | Old Mutual |
| OM | Omni-Lite Industries |
| OM | Organic Merchants |
| OMA | One Madison Avenue |
| OMA | Online Marketing Agency |
| OMAC | Objective Medical Assessments Corp |
| OMAC | Old Man's Aircraft Company |
| OMAI | Outsource Marketing Associates, Inc. |
| OMB | On Market Boston |
| OMBAS | Optimal Medical Benefit Administrative Services (medical insurance company; Unionville, Ontario, Can |
| OMC | Odisha Mining Corporation |