| O.N.E. (Our Nastiest Effort) | De Struise Brouwers | Belgian Dark Strong Ale | 10.0% |
| O.P. (Sole Composition Series) | Upright Brewing Company | American Stout | |
| O.P.W. | Fiddlehead Brewing | American Pale Wheat Beer | 5.5% |
| O.T.I.S. (Oh This Is Sour) | Strangeways Brewing | Wild Ale | 5.0% |
| O.T.I.S. Gin barrel aged | Strangeways Brewing | Wild Ale | 5.0% |
| O.T.I.S. Tequila Barrel Aged | Strangeways Brewing | | 5.0% |
| O.W.K. | Side Project | American Imperial Stout | 15.0% |
| O/O & STIGBERGETS IMPERIAL IPA | Stigbergets Bryggeri | Imperial IPA | 8.0% |
| O/Sour 2022 | Åben | Gose | 4.5% |
| Oachkatzlschwoaf | Urban Chestnut Brewing Company | Märzen | 5.4% |
| Oak & Dagger | Vocation Brewery | American Stout | 7.5% |
| Oak & Mirrors | Brehon Brewhouse | | 7.5% |
| Oak & Orchard Dark Sour with Plums Aged in Whiskey Barrels | Epic Brewing Company | Wild Ale | 7.7% |
| Oak + Age; Vanilla From Tacoma To Vladivostok With Love | Sig Brewing | Russian Imperial Stout | 12.5% |
| Oak + Instinct | Wolves & People Farmhouse Brewery | Wild Ale | 6.4% |