| Maple Lawn Brewery | 110 Mulberry Ave | Pomeroy | Ohio | 45769-1004 | United States | micro | |
| March First Brewing | 7885 E Kemper Rd | Cincinnati | Ohio | 45249-1622 | United States | brewpub | |
| Marietta Brewing Co | 167 Front St | Marietta | Ohio | 45750-3125 | United States | brewpub | |
| Market Garden Brewery | 1849 W 24th St | Cleveland | Ohio | 44113 | United States | micro | |
| Market Garden Brewery | 1947 W 25th St | Cleveland | Ohio | 44113-3418 | United States | micro | |
| Masthead Brewing Co | 1261 Superior Ave E | Cleveland | Ohio | 44114-3204 | United States | brewpub | |
| Maumee Bay Brewing Co | 27 Broadway St Ste A | Toledo | Ohio | 43604-8701 | United States | brewpub | |
| McArthur's Brew House | 2721 Front St | Cuyahoga Falls | Ohio | 44221-1904 | United States | micro | |
| MillerCoors Brewing Co - Trenton | 2525 Wayne Madison Rd | Trenton | Ohio | 45067-9760 | United States | large | |
| Millersburg Brewing | 60 E Jackson St | Millersburg | Ohio | 44654-1257 | United States | brewpub | |
| Missing Falls Brewery | | Akron | Ohio | 44311-1079 | United States | planning | |
| Missing Mountain Brewing Company | 2811 Front St | Cuyahoga Falls | Ohio | 44262 | United States | brewpub | |
| Modern Methods Brewing Company | 125 David Grohl Alley | Warren | Ohio | 44481 | United States | micro | |
| Moeller Brew Barn | 8016 Marion Dr | Maria Stein | Ohio | 45860-8706 | United States | micro | |
| Moerlein Lager House | 115 Joe Nuxhall Way | Cincinnati | Ohio | 45202-4143 | United States | brewpub | |
| Monzula Farm Brewery / Vineyard 22 | 83800 Monzula Rd | Cadiz | Ohio | 43907 | United States | micro | |
| Mosaic Brewing | | Lancaster | Ohio | 43130-4308 | United States | planning | |
| Mother Stewart's Brewing Co | 109 W North St | Springfield | Ohio | 45504-2546 | United States | micro | |
| Mt. Carmel Brewing Co | 4362 Mount Carmel Tobasco Rd | Cincinnati | Ohio | 45244-2338 | United States | micro | |
| Mucky Duck Brewery | 4019 S Main St | Akron | Ohio | 44319-3668 | United States | brewpub | |
| Multiple Brewing Company | 82 W Washington St | Nelsonville | Ohio | 45764-1135 | United States | micro | |
| Municipal Brew Works | 20 High St | Hamilton | Ohio | 45011-2709 | United States | micro | |
| Muskellunge Brewing Company | 425 5th St NW | Canton | Ohio | 44702 | United States | micro | |
| Nano Brew Cleveland | 1859 W 25th St | Cleveland | Ohio | 44113 | United States | brewpub | |
| Narrow Path Brewing Company | 106 Karl Brown Way | Loveland | Ohio | 45140-2902 | United States | micro | |
| Neon Groundhog Brewery - Majestic Oak Winery | 13554 Mohler Rd | Grand Rapids | Ohio | 43522-9648 | United States | micro | |
| New Bremen Brewing Company | | New Bremen | Ohio | 45869-1328 | United States | planning | |
| Nine Giant Brewing | 6095 Montgomery Rd | Cincinnati | Ohio | 45213-1617 | United States | brewpub | |
| Noble Beast Brewing Co. | 1470 Lakeside Ave E | Cleveland | Ohio | 44114-1137 | United States | brewpub | |
| Noble Creature Cask House | 126 E Rayen Ave | Youngstown | Ohio | 44503-1619 | United States | brewpub | |
| Nocterra Brewing Co | 41 Depot St | Powell | Ohio | 43065 | United States | micro | |
| North High Brewing | 1125 Cleveland Ave | Columbus | Ohio | 43201-2900 | United States | micro | |
| Northern Row Brewery & Distillery | 111 W McMicken Ave | Cincinnati | Ohio | 45202-4915 | United States | micro | |
| Nowhere In Particular Brewing Company | 6826 Loop Rd | Dayton | Ohio | 45459-2159 | United States | proprietor | |
| Numbers Brewing Company | 127 N Beaver St | Lisbon | Ohio | 44432-1121 | United States | brewpub | |
| Off Track Brewing Company | 227 Stark Street | Cincinnati | Ohio | 45214 | United States | micro | |
| Ohio Brewing Company | 2250 Front St | Cuyahoga Falls | Ohio | 44221-2510 | United States | micro | |
| Old Dog Alehouse & Brewery | 13 W William St | Delaware | Ohio | 43015 | United States | micro | |
| Old Firehouse Brewery | 237 W Main St | Williamsburg | Ohio | 45176-1342 | United States | micro | |
| Old Mill Craft Beer | 2376 State Route 850 | Bidwell | Ohio | 45614-9590 | United States | micro | |
| Olentangy River Brewing Company | 303 Green Meadows Dr S | Lewis Center | Ohio | 43035 | United States | micro | |
| On The Fly Brewing Company | | Sunbury | Ohio | 43074-9022 | United States | planning | |
| Outerbelt Brewing Company | | Carroll | Ohio | 43112 | United States | planning | |
| Paladin Brewing | 6520 Mahoning Ave | Austintown | Ohio | 44515-2012 | United States | micro | |
| Paradigm Shift Brewing | 128 North Ave NE | Massillon | Ohio | 44646-5526 | United States | micro | |
| Paradune Brewing | 10551 1/2 County Rd 286 | Huntsville | Ohio | 43324 | United States | micro | |
| Paradune Brewing Company | 20707 Township Rd 119 | Belle Center | Ohio | 43310 | United States | micro | |
| Patron Saints Brewery | 4730 W Bancroft St #8 | Toledo | Ohio | 43615 | United States | micro | |
| Pedestrian Brewing | | Lakewood | Ohio | 44107-3309 | United States | planning | |
| Permission Brewing Company | | Columbus | Ohio | 43004 | United States | planning | |