| OB-1 Certified Organic Ale | Snake River Brewing | English Brown Ale | 4.9% |
| OB.LIV.I.OUS | Griffin Claw | Wheatwine | 13.0% |
| Obamagang Inauguration Ale | Brewery Ommegang | American Stout | |
| Obamanator Maibock | Wynkoop Brewing | Maibock | |
| Obedience | Seedy Brewing | Saison | 8.8% |
| Obeisance | Von Ebert | | |
| Obelus | Transient Artisan Ales | | |
| Obergärig / Münster Alt | Brauerei und Altbierkche Pinkus Mller | American Brown Ale | |
| Oberly's Barrel Aged Irish Coffee Stout | Riverlands Brewing Company | American Imperial Stout | 12.0% |
| Oberon | Bell's Brewery, Inc. | American Pale Wheat Beer | 5.8% |
| Oberon Eclypse | Bell's Brewery, Inc. | | |
| OBF | AleSmith Brewing Company | Flanders Oud Bruin | 7.0% |
| Obi Owl Kenobi | Brouwerij het Uiltje | American IPA | 7.2% |
| The Object | Earnest Brew Works | | 8.2% |
| The Object of Devotion | Floodland Brewing | | |