| Oloroso Cask | Innis & Gunn | English Strong Ale | 7.4% |
| Olympe | Broadway Pub | Saison | 3.5% |
| Omega | Alvinne Picobrouwerij | Wild Ale | 6.0% |
| Omega | Brouwerij Alvinne | Lambic | |
| Omega Midnight | Ale Syndicate Brewers | Foreign / Export Stout | 9.5% |
| Omega Point | Olde Hickory Brewery | American Barleywine | 10.0% |
| Omegatex | Fort George Brewery | Imperial IPA | 9.9% |
| Omen Belgian Raspberry Stout (Apocalypse Series) | Elysian Brewing Co. | American Stout | 7.2% |
| Omerta | Bellwoods Brewery | American Pale Ale | 5.0% |
| OMG | Rapp Brewing Company | American Strong Ale | 20.0% |
| Omission pale ale | Widmer Brothers Brewing | | |
| Ommegang Adoration | Brewery Ommegang | Belgian Dark Strong Ale | 10.0% |
| Ommegang XV - 15th Anniversary Ale | Brewery Ommegang | Belgian Dark Strong Ale | 9.6% |
| Ommegeddon | Brewery Ommegang | Wild Ale | 8.0% |
| Omniscience & Proselytism | Jester King Craft Brewery | Wild Ale | 5.0% |