| Brewery | Location |
|---|---|
| Only Child | Northbrook, IL |
| Onopa Brewing | Milwaukee, Wisconsin |
| Onsala Hantverks Bryggeri | Onsala, Sweden |
| Oosteke Brouwers | Gavere |
| Oozlefinch Beers & Blending | Fort Monroe, Virginia |
| Ope! Brewing Co. | West Allis, Wisconsin |
| Open Water Brewery | Knutsboda, Finland |
| Ophiussa Brewing Company | Setúbal, Portugal |
| Opperbacco | Italy |
| Oppigårds Bryggeri | Hedemora, Sweden |
| Oppigårds Bryggeri/Närke Kulturbryggeri | |
| Oproer Brouwerij | Utrecht, Netherlands |
| Oracle Brewing Company | Saginaw, MI |
| Orange Belt Brewing | Gulfport, FL |
| Orange Blossom Brewing Company | Orlando, Florida |