| Brewery | Location |
|---|---|
| Oregon Trail Brewery | Corvallis, Oregon |
| Oriental Brewery | Korea, Republic of |
| Origin Beer Project | Providence, Rhode Island |
| Original Basil T's | Red Bank, New Jersey |
| Orkney Brewery | Orkney, United Kingdom |
| Orlando Brewing | Orlando, Florida |
| Orlio Organic | South Burlington, Vermont |
| Orpheus Brewing | Atlanta, Georgia |
| Os Três Cervejeiros | Porto |
| Oshlag | |
| Oskar Blues / Cigar City | |
| Oskar Blues Brewery | Lyons, CO |
| Oso | Plover, WI |
| Ostankinskij Pivovarennij Zavod | Moskva |
| Oswald |