| Oscar's Double Chocolate Milk Stout | Sand Creek Brewing Company | American Imperial Stout | 10.0% |
| Oscars | Sand Creek Brewing Company | Oatmeal Stout | 4.5% |
| Oscillate Wildly | Strangeways Brewing | Wild Ale | 10.0% |
| Oscillation | Brasserie du Bas-Canada | American Barleywine | 11.9% |
| Oscuro Org | Commonwealth Brewing Co. | | |
| Oseka | The Garden Brewery | New England IPA | 6.2% |
| Osiris | 3rd Sign Brewery | American Imperial Stout | 9.0% |
| Osiris | Sun King Brewing Company | American Pale Ale | 5.6% |
| Osiris-Rex | Black Project Spontaneous & Wild Ales | | 9.0% |
| Oskar HMS Ark Royal | Noctem Artisans Brasseurs | New England IPA | 7.0% |
| Oskar KMS Bismarck | Noctem Artisans Brasseurs | American IPA | 7.0% |
| Oskar KMS Cossack | Noctem Artisans Brasseurs | New England IPA | 7.0% |
| Osmosis | Sapwood Cellars | Czech Amber Lager | 5.8% |
| Osmotar | Plan Bee Farm Brewery | Wild Ale | |
| Oso | Cismontane Brewing | English Porter | 10.0% |