| Acronym | Definition |
|---|
| OMG | Oh My God (chat) |
| OMG | Object Management Group (non-profit organization that oversees CORBA) |
| OMG | Oh My Gosh |
| OMG | Oh My Goodness |
| OMG | Omega (gaming) |
| OMG | Over My Grave |
| OMG | Oh My Gatos |
| OMG | Officially Miss Guided (band) |
| OMG | Operazione Mato Grosso (Italian labor movement) |
| OMG | Operations Managers Group (various organizations) |
| OMG | Obama Must Go |
| OMG | Organization Management Group (various locations) |
| OMG | Object Model Guide |
| OMG | Object Management Group |
| OMG | Old Magazines (pulp and paper industry) |
| OMG | Omnicom Media Group |
| OMG | Oh My Gods (for Wiccans/Pagans or other polytheistic religions) |
| OMG | Oh My Goth |
| OMG | Outlaw Motorcycle Gang |
| OMG | One Man Gang |
| OMG | Operation Market Garden (gaming) |
| OMG | Oh Em Gee (clothing business) |
| OMG | Oh My Goddess! (anime) |
| OMG | Oh My Gravy |
| OMG | One Mighty God |
| OMG | Open Management Group (computer industry consortium) |
| OMG | Oslo Marine Group (St. Petersburg, Russia) |
| OMG | Order of Mapungubwe (honor; South Africa) |
| OMG | Ocean Media Group (UK) |
| OMG | Ocular Myasthenia Gravis (Disease) |
| OMG | Original Mac Games (contest) |
| OMG | Oh My Ghost |
| OMG | Operational Maneuver Group |
| OMG | Oh My Gender |
| OMG | Open Messaging Gateway |
| OMG | Online Music Group |
| OMG | Order Management Group |
| OMG | Osseo-Maple Grove (two city area in Minnesota) |
| OMG | Oversized Male Genital |
| OMG | Overly Managed Garden |
| OMG | Ow, My Groin |