| Obliteration VI | Midnight Sun Brewing Co. | Imperial IPA | 8.5% |
| Oblivion | Wicked Weed | Wild Ale | 8.5% |
| Obovoid Empirical Stout | Boulder Beer Company | American Imperial Stout | 8.0% |
| Obscura | Troubadour | | |
| Obscura Arborea | Telegraph Brewing Company | Flanders Oud Bruin | 9.0% |
| Obscura Aurantium | Telegraph Brewing Company | American Barleywine | 10.0% |
| Obscura Cacao | Telegraph Brewing Company | Herb and Spice Beer | 7.3% |
| Obscura Peche | Telegraph Brewing Company | Wild Ale | 6.0% |
| Obscuritas | Driftwood Brewery | Wild Ale | 7.6% |
| Obscurite | Ithaca Beer Company | | 10.0% |
| Obscuro & Nimbosus | Avery Brewing Company | Wild Ale | 8.1% |
| Obsidian | Cameron's Brewing | | 9.2% |
| Obsidian Rum Barrel | Camerons Brewery Company | | |
| Obsidian Stout | Deschutes Brewery | American Stout | 6.4% |
| OBX Beer | Weeping Radish Eco Farm & Brewery | Kölsch | 6.0% |