| Omnipollo, Siren Craft Brew & Mike Bates | |
| On Tap Bistro & Brewery | San Diego, California |
| One Trick Pony | Lansing |
| Onion Pub & Brewery | Lake Barrington, Illinois |
| Only Child | Northbrook, IL |
| Onopa Brewing | Milwaukee, Wisconsin |
| Oppigårds Bryggeri | Hedemora, Sweden |
| Orange Belt Brewing | Gulfport, FL |
| Orange Blossom Brewing Company | Orlando, Florida |
| Orange Blossom Pilsner | |
| Oranjeboom Bierbrouwerij B. V. | |
| Orchard Street Brewery | Bellingham, Washington |
| Ore Dock Brewing Company | Marquette, Michigan |
| Örebro Brygghus | Örebro, Sweden |
| Oregon Trader Brewing | Albany, Oregon |