| IIInx International Ink CO | Appleton | WI | Chemical Manufacturing325910 | — | ◐ LIKELY ACTIVE |
| IPIrving Polishing and Mfg CO INC | Kenosha | WI | Fabricated Metal Product Manufacturing332813 | 20-99 | ◐ LIKELY ACTIVE |
| INIVI North, Inc. | Greenville | WI | Fabricated Metal Product Manufacturing332322 | 100-499 | ◐ LIKELY ACTIVE |
| JSJ&D Sales Inc. of Eau Claire WI | Eau Claire | WI | Machinery Manufacturing333413 | 20-99 | ◐ LIKELY ACTIVE |
| JWJen-ter Wire & Element, INC. | Fox Lake | WI | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| JEJohnson Electric Coil Co., Inc | Antigo | WI | Electrical Equipment, Appliance & Component Manufacturing335311 | 20-99 | ◐ LIKELY ACTIVE |
Johnsonville LLC | Sheboygan Falls | WI | Food Manufacturing311612 | 500+ | ◐ LIKELY ACTIVE |
| JSJohnsonville Sausage LLC | Sheboygan Falls | WI | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
Jones Dairy Farm South | Fort Atkinson | WI | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| KLKdv Label CO INC | Waukesha | WI | Printing and Related Support Activities323110 | 100-499 | ◐ LIKELY ACTIVE |
| KCKeenline Conveyor Systems, LLC | Omro | WI | Machinery Manufacturing333922 | 20-99 | ◐ LIKELY ACTIVE |
| KMKelsch Machine Corporation | Belleville | WI | Fabricated Metal Product Manufacturing332710 | 20-99 | ◐ LIKELY ACTIVE |
| KLKemps LLC | Cedarburg | WI | Food Manufacturing311511 | — | ◐ LIKELY ACTIVE |
| KFKewaunee Fabrications LLC | Kewaunee | WI | Fabricated Metal Product Manufacturing332999 | — | ◐ LIKELY ACTIVE |
| KCKimberly Clark CORP | Marinette | WI | Paper Manufacturing322120 | 100-499 | ◐ LIKELY ACTIVE |
| KCKlondike Cheese Co. | Monroe | WI | Food Manufacturing311513 | 100-499 | ◐ LIKELY ACTIVE |
| KKKolbe & Kolbe Millwork Co., Inc - Main Plant | Wausau | WI | Wood Product Manufacturing321910 | 500+ | ◐ LIKELY ACTIVE |
| KIKrones INC | Franklin | WI | Machinery Manufacturing333990 | 500+ | ◐ LIKELY ACTIVE |
| KIKtm Industries, INC | Richfield | WI | Machinery Manufacturing333511 | 20-99 | ◐ LIKELY ACTIVE |
Lakeside Foods INC. | Random Lake | WI | Food Manufacturing311411 | 20-99 | ◐ LIKELY ACTIVE |
| LPLakes Precision Inc. | Three Lakes | WI | Machinery Manufacturing333515 | 20-99 | ◐ LIKELY ACTIVE |
| LOLand O'lakes - Hillsboro | Hillsboro | WI | Food Manufacturing311512 | 20-99 | ◐ LIKELY ACTIVE |
| LMLange Machine & Tool CO LLC | Merrill | WI | Fabricated Metal Product Manufacturing332710 | 1-19 | ◐ LIKELY ACTIVE |
| LFLang Furniture, Inc. | Marshfield | WI | Furniture and Related Product Manufacturing337122 | 20-99 | ◐ LIKELY ACTIVE |
| LHLapham Hickey Steel Corporation | Oshkosh | WI | Fabricated Metal Product Manufacturing332999 | 100-499 | ◐ LIKELY ACTIVE |
| LFLegacy Flexo | Green Bay | WI | Printing and Related Support Activities323111 | 100-499 | ◐ LIKELY ACTIVE |
| LSLejeune Steel CO. (403 Thorp) | Thorp | WI | Fabricated Metal Product Manufacturing332312 | 20-99 | ◐ LIKELY ACTIVE |
| LWLincoln Wood Products | Merrill | WI | Wood Product Manufacturing321911 | 100-499 | ◐ LIKELY ACTIVE |
| LMLoos Machine and Automation LLC | Colby | WI | Machinery Manufacturing333241 | 100-499 | ◐ LIKELY ACTIVE |
Louisiana-pacific Corporation-tomahawk | Tomahawk | WI | Wood Product Manufacturing321219 | 100-499 | ◐ LIKELY ACTIVE |
| MSM2M Synergy, LLC | Mukwonago | WI | Fabricated Metal Product Manufacturing332710 | 20-99 | ◐ LIKELY ACTIVE |
| MCMadison-kipp Corporation - Sun Prairie | Sun Prairie | WI | Primary Metal Manufacturing331523 | 100-499 | ◐ LIKELY ACTIVE |
Magnetic Technologies Corporation | Middleton | WI | Electrical Equipment, Appliance & Component Manufacturing335312 | — | ◐ LIKELY ACTIVE |
| MFMalone's Fine Sausage, Inc. | Milwaukee | WI | Food Manufacturing311612 | 1-19 | ◐ LIKELY ACTIVE |
| MCManitowoc Cranes Inc- Manitowoc, WI | Manitowoc | WI | Machinery Manufacturing333120 | 20-99 | ◐ LIKELY ACTIVE |
| MPManufacturers Pallet Disposal Inc | Waupaca | WI | Wood Product Manufacturing321920 | 20-99 | ◐ LIKELY ACTIVE |
| MLMaple Leaf Cheesemakers, Inc. | Monroe | WI | Food Manufacturing311511 | 20-99 | ◐ LIKELY ACTIVE |
| MSMarchant Schmidt | Fond Du Lac | WI | Machinery Manufacturing333241 | 20-99 | ◐ LIKELY ACTIVE |
| MIMarsan INC. | Germantown | WI | Fabricated Metal Product Manufacturing332710 | — | ◐ LIKELY ACTIVE |
| MAMathews Archery, Inc | Sparta | WI | Miscellaneous Manufacturing339920 | 100-499 | ◐ LIKELY ACTIVE |
| MPMatrix Packaging Machinery | Grafton | WI | Fabricated Metal Product Manufacturing332810 | 20-99 | ◐ LIKELY ACTIVE |
| MIM-b-w, INC. | Slinger | WI | Machinery Manufacturing333120 | 20-99 | ◐ LIKELY ACTIVE |
Mccain Foods Usa, Inc., Plover, Wisconsin | Wisconsin Rapids | WI | Food Manufacturing311410 | — | ◐ LIKELY ACTIVE |
| MPMenasha Packaging Preprint Group | Neenah | WI | Printing and Related Support Activities323110 | 20-99 | ◐ LIKELY ACTIVE |
| MCMesser Cutting Systems INC | Menomonee Falls | WI | Primary Metal Manufacturing331512 | 100-499 | ◐ LIKELY ACTIVE |
| MIMetalcraft Industries, INC. | Oregon | WI | Fabricated Metal Product Manufacturing332116 | 1-19 | ◐ LIKELY ACTIVE |
| MFMid-city Foundry CORP - United Div | Grafton | WI | Primary Metal Manufacturing331510 | 20-99 | ◐ LIKELY ACTIVE |
| MPMidland Packaging and Display | Franksville | WI | Paper Manufacturing322211 | 100-499 | ◐ LIKELY ACTIVE |
| MLMidor LTD | Elroy | WI | Food Manufacturing311514 | 20-99 | ◐ LIKELY ACTIVE |
| MIMidwest Industrial Fuel INC | La Crosse | WI | Petroleum and Coal Products Manufacturing324121 | 1-19 | ◐ LIKELY ACTIVE |