| MDManternach Development CO. | Friendship | WI | Wood Product Manufacturing321992 | 20-99 | ◇ UNVERIFIED |
| MEMARCK Enterprises LLC | Burlington | WI | Printing and Related Support Activities323111 | 1-19 | ◇ UNVERIFIED |
| MWMarc Wolf LTD. | Milwaukee | WI | Leather and Allied Product Manufacturing316993 | 1-19 | ◇ UNVERIFIED |
| MEMarmax Enterprises, Inc. | Richfield | WI | Machinery Manufacturing333511 | 1-19 | ◇ UNVERIFIED |
| MCMARW Corp | Oconto | WI | Fabricated Metal Product Manufacturing332812 | 1-19 | ◇ UNVERIFIED |
| MJMaster Jig Grinding Specialists, Inc | Germantown | WI | Machinery Manufacturing333512 | 1-19 | ◇ UNVERIFIED |
| MTMaster Tool and Mold | Grafton | WI | Machinery Manufacturing333514 | 1-19 | ◇ UNVERIFIED |
| MMMatrix Machining, Inc. | Town of Clayton | WI | Machinery Manufacturing333999 | 1-19 | ◇ UNVERIFIED |
| MCMcclintock Cabinets INC. | Appleton | WI | Furniture and Related Product Manufacturing337110 | 1-19 | ◇ UNVERIFIED |
| MIMCG, Inc | Watertown | WI | Printing and Related Support Activities323111 | 1-19 | ◇ UNVERIFIED |
| MWMcs Woodworking, LLC | Milwaukee | WI | Wood Product Manufacturing321918 | 1-19 | ◇ UNVERIFIED |
| MFMerton Feed Company, LLC | Merton | WI | Food Manufacturing311119 | 1-19 | ◇ UNVERIFIED |
| MTMetalcraft Tool & Die INC. | Ixonia | WI | Primary Metal Manufacturing331210 | 1-19 | ◇ UNVERIFIED |
| MWMetro Welding & Fabricating, INC. | Big Bend | WI | Fabricated Metal Product Manufacturing332710 | 1-19 | ◇ UNVERIFIED |
| MQMicrostar Quality Services LLC | Green Bay | WI | Fabricated Metal Product Manufacturing332431 | — | ◇ UNVERIFIED |
| MCMid City Precision LLC | Wausau | WI | Fabricated Metal Product Manufacturing332710 | 1-19 | ◇ UNVERIFIED |
| MMMid-point Machine, INC. | Glenbeulah | WI | Fabricated Metal Product Manufacturing332710 | — | ◇ UNVERIFIED |
| MHMidwest Harness and Cable | Greenville | WI | Electrical Equipment, Appliance & Component Manufacturing335999 | 1-19 | ◇ UNVERIFIED |
| MRMidwest Rock Tops, LLC | Madison | WI | Nonmetallic Mineral Product Manufacturing327991 | 1-19 | ◇ UNVERIFIED |
| MSMidwest Specialty Products LLC | Winneconne | WI | Paper Manufacturing322299 | 20-99 | ◇ UNVERIFIED |
| MSMidwest Stainless Technologies, LLC | Menomonie | WI | Machinery Manufacturing333992 | 100-499 | ◇ UNVERIFIED |
| MCMike's Country Meats, LLC. | Tigerton | WI | Food Manufacturing311613 | 1-19 | ◇ UNVERIFIED |
| M4Milwaukee - 404 S 116th St | Milwaukee | WI | Primary Metal Manufacturing331511 | 20-99 | ◇ UNVERIFIED |
| MPMilwaukee Pretzel Company, LLC | Milwaukee | WI | Food Manufacturing311812 | 20-99 | ◇ UNVERIFIED |
| MOMJH of Janesville, LLC | Janesville | WI | Furniture and Related Product Manufacturing337910 | 1-19 | ◇ UNVERIFIED |
| MBMobCraft Beer Inc. | Milwaukee | WI | Beverage and Tobacco Product Manufacturing312120 | 1-19 | ◇ UNVERIFIED |
| MCModern Cabinet Making, LLC | Kenosha | WI | Furniture and Related Product Manufacturing337212 | 1-19 | ◇ UNVERIFIED |
| MOModern of Marshfield | Marshfield | WI | Furniture and Related Product Manufacturing337127 | 20-99 | ◇ UNVERIFIED |
| MCMotorsport Composites, Inc. | Grafton | WI | Electrical Equipment, Appliance & Component Manufacturing335991 | 1-19 | ◇ UNVERIFIED |
| MNMount N Screenery, Inc | Oostburg | WI | Printing and Related Support Activities323113 | 1-19 | ◇ UNVERIFIED |
| MGMpp Group LLC | Mequon | WI | Chemical Manufacturing325412 | 1-19 | ◇ UNVERIFIED |
| MMMsm Machine Works INC | Janesville | WI | Machinery Manufacturing333293 | 1-19 | ◇ UNVERIFIED |
| MPMurmac Paint Mfg., INC. | Beloit | WI | Chemical Manufacturing325510 | 1-19 | ◇ UNVERIFIED |
| NGNational Graphic Solutions | Appleton | WI | Printing and Related Support Activities323117 | 20-99 | ◇ UNVERIFIED |
| NSNatural Stone Veneers International, INC. | Fond Du Lac | WI | Nonmetallic Mineral Product Manufacturing327991 | — | ◇ UNVERIFIED |
 Ndt Solutions LLC | New Richmond | WI | Computer and Electronic Product Manufacturing334519 | — | ◇ UNVERIFIED |
| NBNeenah Brass & Aluminum Foundry CO | Neenah | WI | Primary Metal Manufacturing331522 | — | ◇ UNVERIFIED |
| NMNemadji Management LLC | Osceola | WI | Food Manufacturing311942 | 20-99 | ◇ UNVERIFIED |
| NMNew Morning Coffee Roasters, Inc. | Appleton | WI | Food Manufacturing311920 | 1-19 | ◇ UNVERIFIED |
| NVNew View Woodworks LLC | Fox Lake | WI | Furniture and Related Product Manufacturing337212 | 1-19 | ◇ UNVERIFIED |
| NPNexGen Plastics, Inc. | Salem Lakes | WI | Plastics and Rubber Products Manufacturing326199 | 1-19 | ◇ UNVERIFIED |
| NCNimco Controls, Inc. | Sturtevant | WI | Fabricated Metal Product Manufacturing332912 | 1-19 | ◇ UNVERIFIED |
| NPNorthern Products of Wisc., INC. | Florence | WI | Wood Product Manufacturing321113 | 1-19 | ◇ UNVERIFIED |
| NPNorthwoods Pallets, LLC | Chippewa Falls | WI | Wood Product Manufacturing321920 | 20-99 | ◇ UNVERIFIED |
| NINtm, INC. | Elroy | WI | Plastics and Rubber Products Manufacturing326199 | 20-99 | ◇ UNVERIFIED |
| OEOakfield Enterprises INC | Oakfield | WI | Fabricated Metal Product Manufacturing332710 | 1-19 | ◇ UNVERIFIED |
| OROak Ridge Custom Cabinets, INC. | Green Bay | WI | Furniture and Related Product Manufacturing337110 | 1-19 | ◇ UNVERIFIED |
| OIOFP Ingredients, LLC | Oconomowoc | WI | Food Manufacturing311999 | 1-19 | ◇ UNVERIFIED |
| OBOne Barrel Brewing Company, LLC | Madison | WI | Beverage and Tobacco Product Manufacturing312120 | 1-19 | ◇ UNVERIFIED |
| OBOostburg Bakery | Oostburg | WI | Food Manufacturing311811 | 1-19 | ◇ UNVERIFIED |
