| OSB Premium Ale | Tomos Watkin and Sons Ltd. | | 4.5% |
| Oscillate Wildly | Strangeways Brewing | Wild Ale | 10.0% |
| Osiris | Sun King Brewing Company | American Pale Ale | 5.6% |
| Oso | Cismontane Brewing | English Porter | 10.0% |
| Oso Furioso | Sudwerk Brewing | Doppelbock | 9.0% |
| Ossian | Inveralmond Brewery | English Pale Mild Ale | 4.1% |
| Ossipioja | Sap House Meadery | | |
| OST Porter | Rogness Brewing Company | English Porter | 5.7% |
| Ostindien | Mariestads | | |
| Ostronporter | Grebbestad bryggeri | | 5.8% |
| Othello | Barrel House Brewing Co. | | 8.7% |
| Othello | Barrelhouse Brewing Co. | | 8.7% |
| Otiose | The Bruery | Wild Ale | |
| Otis Alt | Elk Grove Brewery & Restaurant | American Brown Ale | 5.3% |
| Otra Vez | Sierra Nevada Brewing Co. | Gose | 4.5% |