| Oxbow Brewing Company | |
| Oxus Brewing Company | Winnipeg |
| Oxymore Microbrasserie | Saint-Gilles Lotbinière, Canada |
| Oy Sinebrychoff AB | Kerava, Finland |
| Oyster Bar Bistro and Brewery | Fort Wayne, Indiana |
| Oyster City Brewing Company | Apalachicola |
| Ozark Beer Company | Rogers |
| Pabst Brewing Company | San Antonio, Texas |
| Pacific Beach Brewhouse | Pacific Beach, California |
| Pacific Coast Brewing | Oakland, California |
| Pacific Plate Brewing Company | Monrovia |
| Pacific Rim Brewing | Seattle, Washington |
| Paddock Wood | Saskatoon |
| Palaweño Brewery | Puerto Princesa, Philippines |
| Pale Fire Brewing Co. | Harrisonburg, VA |