| O'Malley's Irish Cream Ale | Weston Brewing Company | Creame Ale | |
| O'Malley's Stout | Weston Brewing Company | American Stout | 5.5% |
| O'SOO Oyster Stout | Benford Brewing | Oatmeal Stout | |
| O-gii | Milwaukee Brewing Company | | |
| O-H! | Triple Digit Brewing Co | | |
| O-Tay Bockwheat | Egan Brewing | | |
| O.B. Vanilla Rye | Honey Pot Meadery | | |
| O.K. Beer | Browar Okocim | | |
| 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.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/O & STIGBERGETS IMPERIAL IPA | Stigbergets Bryggeri | Imperial IPA | 8.0% |
| Oak Aged 1847 Rye Stout | Lavery Brewing Company | Irish Dry Stout | 6.8% |