| Morgan Territory Brewing | 1885 N Macarthur Dr | Tracy | California | 95376-2820 | United States | micro | |
| Mother Earth Brew Co LLC | 2055 Thibodo Rd Ste H | Vista | California | 92081-7991 | United States | regional | |
| Motobrewer | | San Francisco | California | 94112-1330 | United States | planning | |
| Mount Shasta Brewing Co | 360 College Ave | Weed | California | 96094-2706 | United States | micro | |
| Mountain Rambler Brewery | 186 S Main St | Bishop | California | 93514-3415 | United States | micro | |
| Moylan's Brewery & Restaurant | 15 Rowland Way | Novato | California | 94945-5001 | United States | brewpub | |
| Mraz Brewing Company | 2222 Francisco Dr Ste 510 | El Dorado Hills | California | 95762-3766 | United States | micro | |
| Mt Lowe Brewing Company | 150 E Saint Joseph St | Arcadia | California | 91006-2851 | United States | micro | |
| Mumford Brewing Company | 416 Boyd St | Los Angeles | California | 90013-1631 | United States | micro | |
| Napa Palisades Beer Company | 1000 Main St | Napa | California | 94559-2645 | United States | proprietor | |
| Napa Smith Brewery | 101 Yolano Dr | Vallejo | California | 94589-2250 | United States | micro | |
| Napa Valley Brewing Co/ Calistoga Inn | 1250 Lincoln Ave | Calistoga | California | 94515-1741 | United States | brewpub | |
| Naughty Oak Brewing Company | 165 S Broadway St Ste 102 | Orcutt | California | 93455-4627 | United States | micro | |
| Network Brewery | 1824 Carnegie Ave | Santa Ana | California | 92705-5503 | United States | micro | |
| New Bohemia Brewing Co | 1030 41st Ave | Santa Cruz | California | 95062-4447 | United States | brewpub | |
| New English Brewing Co Inc | 11545 Sorrento Valley Rd Ste 305 | San Diego | California | 92121-1322 | United States | micro | |
| New Glory Craft Brewery | 8251 Alpine Ave | Sacramento | California | 95826-4708 | United States | micro | |
| New Helvetia Brewing Company | 1730 Broadway | Sacramento | California | 95818-2320 | United States | micro | |
| Nickel Beer Co | 1485 Hollow Glen Rd | Julian | California | 92036 | United States | micro | |
| No Clue Craft Brewery | 9037 Arrow Rte Ste 170 | Rancho Cucamonga | California | 91730-4433 | United States | micro | |
| Noble Ale Works | 1621 S Sinclair St Ste B | Anaheim | California | 92806-5947 | United States | micro | |
| North Coast Brewing Co Inc. | 455 N Main St | Fort Bragg | California | 95437-3215 | United States | regional | |
| North Park Beer Co. | 3038 University Ave | San Diego | California | 92104-3002 | United States | micro | |
| Northern Pine Brewing | 326 N Horne St | Oceanside | California | 92054-2810 | United States | micro | |
| Nova Brewing Co | 1580 W San Bernardino Rd Ste H | Covina | California | 91722-3457 | United States | micro | |
| Novel Brewing Company | 6510 San Pablo Ave | Oakland | California | 94608-1236 | United States | micro | |
| Novo Brazil Brewing Company | 901 Lane Ave # 100 | Chula Vista | California | 91914-3501 | United States | micro | |
| O'Meara Bros. Brewing Company | 901 Bevins St | Lakeport | California | 95453-8778 | United States | brewpub | |
| Oak Grove Brewing Company | | Glendale | California | 91208-1836 | United States | planning | |
| Oak Hills Brewing | 12221 Poplar St Ste 3 | Hesperia | California | 92344-9287 | United States | micro | |
| Oak Park Brewing Co | 3514 Broadway | Sacramento | California | 95817-2825 | United States | brewpub | |
| Oakland United Beerworks | 3775 Alameda Ave Ste G | Oakland | California | 94601-3920 | United States | micro | |
| Ocean Beach Brewery | 5041 Newport Ave | San Diego | California | 92107-3009 | United States | brewpub | |
| Oceanside Ale Works | 1800 Ord Way | Oceanside | California | 92056-1502 | United States | micro | |
| Oceanside Brewing Company | 312 Via Del Norte | Oceanside | California | 92058-1232 | United States | micro | |
| Oda Restaurant | 1500 Owens St | San Francisco | California | 94158-2334 | United States | brewpub | |
| Off the Grid Brewing Co | 13615 John Glenn Rd Ste A | Apple Valley | California | 92308-5730 | United States | micro | |
| Offshoot Beer Co. | 737 Dunn Way | Placentia | California | 92870 | United States | micro | |
| Oggi's Sports Brewhouse Pizza - Apple Valley | 19201 Bear Valley Rd Ste D | Apple Valley | California | 92308-2704 | United States | brewpub | |
| Oggi's Sports Brewhouse Pizza - Upland | 1173 E 19th St | Upland | California | 91784 | United States | brewpub | |
| Oggis Pizza & Brewing Co - Carmel Mountain Ranch | 10155 Rancho Carmel Dr | San Diego | California | 92128-3609 | United States | brewpub | |
| Oggis Pizza & Brewing Co - Mission Valley | 2245 Fenton Pkwy Ste 108 Fenton Marketplace | San Diego | California | 92108-4737 | United States | brewpub | |
| Ogopogo Brewing | 864 Commercial Ave | San Gabriel | California | 91776 | United States | micro | |
| Ohana Brewing Co | 1756 E 23rd St | Los Angeles | California | 90058-1012 | United States | micro | |
| OK3 Brewing Company | 12913 17th Ave | Lemoore | California | 93245-9485 | United States | micro | |
| Ol' Republic Brewery | 124 Argall Way | Nevada City | California | 95959-3002 | United States | micro | |
| Ol' Republic Brewery Rancho Cordova | 11151 Trade Center Dr Ste 104 | Rancho Cordova | California | 95670 | United States | micro | |
| Old 290 Brewery | | Santa Ana | California | 92704-7463 | United States | planning | |
| Old Bus Tavern | 3193 Mission St | San Francisco | California | 94110-4515 | United States | brewpub | |
| Old Country Brewing | | Fairfield | California | 94533-7790 | United States | planning | |