| SASellars Absorbent Materials CO | Milwaukee | WI | Paper Manufacturing322291 | 100-499 | ◐ LIKELY ACTIVE |
| SFSeneca Foods CORP | Baraboo | WI | Fabricated Metal Product Manufacturing332430 | 100-499 | ◐ LIKELY ACTIVE |
| SFSeneca Foods CORP | Clyman | WI | Food Manufacturing311000 | 100-499 | ◐ LIKELY ACTIVE |
| SFSeneca Foods CORP | Ripon | WI | Food Manufacturing311420 | 500+ | ◐ LIKELY ACTIVE |
| SFSensient Flavors INC | Juneau | WI | Food Manufacturing311999 | 20-99 | ◐ LIKELY ACTIVE |
| SPServer Products Inc | Richfield | WI | Machinery Manufacturing333310 | 100-499 | ◐ LIKELY ACTIVE |
| SPSheboygan Paint CO. | Sheboygan | WI | Chemical Manufacturing325510 | 20-99 | ◐ LIKELY ACTIVE |
| SShurpac | Racine | WI | Wood Product Manufacturing321920 | 20-99 | ◐ LIKELY ACTIVE |
| SLSignicast LLC - Brown Deer | Milwaukee | WI | Primary Metal Manufacturing331510 | 100-499 | ◐ LIKELY ACTIVE |
| SMSimply Mfg INC | Prairie Du Sac | WI | Fabricated Metal Product Manufacturing332312 | 1-19 | ◐ LIKELY ACTIVE |
| SASkana Aluminum Company | Manitowoc | WI | Primary Metal Manufacturing331314 | 100-499 | ◐ LIKELY ACTIVE |
| SMSonoco Metal Packaging LLC | Milwaukee | WI | Fabricated Metal Product Manufacturing332430 | 100-499 | ◐ LIKELY ACTIVE |
| SFSpirit Fabs INC | Wrightstown | WI | Fabricated Metal Product Manufacturing332310 | 20-99 | ◐ LIKELY ACTIVE |
| SPStandard Process INC | Palmyra | WI | Food Manufacturing311990 | 500+ | ◐ LIKELY ACTIVE |
| SLState Line Distillery | Madison | WI | Beverage and Tobacco Product Manufacturing312140 | 1-19 | ◐ LIKELY ACTIVE |
| SCSt. Croix Castings, INC. | Woodville | WI | Primary Metal Manufacturing331524 | 20-99 | ◐ LIKELY ACTIVE |
| SCSt Croix of Park Falls LTD | Park Falls | WI | Miscellaneous Manufacturing339920 | 100-499 | ◐ LIKELY ACTIVE |
| SCSt Croix Press INC | New Richmond | WI | Printing and Related Support Activities323110 | 20-99 | ◐ LIKELY ACTIVE |
| SKSteel King Industries INC | Stevens Point | WI | Fabricated Metal Product Manufacturing332312 | 20-99 | ◐ LIKELY ACTIVE |
| SISteelwind Industries | Oak Creek | WI | Chemical Manufacturing325510 | 20-99 | ◐ LIKELY ACTIVE |
| STStoughton Trailers, LLC - Plants 5&6 | Stoughton | WI | Transportation Equipment Manufacturing336210 | 100-499 | ◐ LIKELY ACTIVE |
| SKStraus Knitting Mills Inc | Saint Croix Falls | WI | Textile Mills313230 | 20-99 | ◐ LIKELY ACTIVE |
| SDSuperior Diesel, INC. | Rhinelander | WI | Machinery Manufacturing333618 | 20-99 | ◐ LIKELY ACTIVE |
| SPSuperior Paper Products | Marshfield | WI | Paper Manufacturing322299 | 20-99 | ◐ LIKELY ACTIVE |
| SMSussek Machine CORP | Waterloo | WI | Fabricated Metal Product Manufacturing332710 | 20-99 | ◐ LIKELY ACTIVE |
| SISussex Im, INC. | Sussex | WI | Plastics and Rubber Products Manufacturing326199 | 100-499 | ◐ LIKELY ACTIVE |
| SWSwanson Wiper Corporation | Oshkosh | WI | Paper Manufacturing322299 | 20-99 | ◐ LIKELY ACTIVE |
| TTechniplas | Nashotah | WI | Plastics and Rubber Products Manufacturing326100 | 100-499 | ◐ LIKELY ACTIVE |
| TJThe Jor-mac CO INC. | Lomira | WI | Fabricated Metal Product Manufacturing332322 | 100-499 | ◐ LIKELY ACTIVE |
| TSThermal Spray Technologies | Sun Prairie | WI | Chemical Manufacturing325510 | 100-499 | ◐ LIKELY ACTIVE |
| TLTherma-stor LLC | Madison | WI | Machinery Manufacturing333415 | 100-499 | ◐ LIKELY ACTIVE |
| TVThe Vollrath Company, LLC | Sheboygan | WI | Fabricated Metal Product Manufacturing332110 | 500+ | ◐ LIKELY ACTIVE |
| TCThorcraft Custom Kitchens LLC | Thorp | WI | Furniture and Related Product Manufacturing337110 | 20-99 | ◐ LIKELY ACTIVE |
| TEThorp Equipment INC | Thorp | WI | Fabricated Metal Product Manufacturing332312 | 100-499 | ◐ LIKELY ACTIVE |
| T1Tier 1 Nutritionals, Inc. | Madison | WI | Food Manufacturing311119 | 20-99 | ◐ LIKELY ACTIVE |
| TLTigerton Lumber CO | Tigerton | WI | Wood Product Manufacturing321113 | 20-99 | ◐ LIKELY ACTIVE |
| TQToms Quality Millwork and Hardwoods INC | Campbellsport | WI | Wood Product Manufacturing321918 | 100-499 | ◐ LIKELY ACTIVE |
| TCTorrance Casting INC | La Crosse | WI | Primary Metal Manufacturing331510 | 20-99 | ◐ LIKELY ACTIVE |
| TBTrachte Building Systems, INC. | Sun Prairie | WI | Fabricated Metal Product Manufacturing332311 | 100-499 | ◐ LIKELY ACTIVE |
| TMTriangle Manufacturing Company | Oshkosh | WI | Fabricated Metal Product Manufacturing332116 | 20-99 | ◐ LIKELY ACTIVE |
| TTTriangle Tool, LLC | Milwaukee | WI | Fabricated Metal Product Manufacturing332710 | — | ◐ LIKELY ACTIVE |
| TITrimen Industrial LLC | Belgium | WI | Fabricated Metal Product Manufacturing332710 | 20-99 | ◐ LIKELY ACTIVE |
| TCTriple Crown Products INC | Mukwonago | WI | Printing and Related Support Activities323113 | 100-499 | ◐ LIKELY ACTIVE |
| UJUfp Janesville LLC | Janesville | WI | Wood Product Manufacturing321114 | 20-99 | ◐ LIKELY ACTIVE |
| UAUnited Alloy, INC. | Janesville | WI | Fabricated Metal Product Manufacturing332312 | 500+ | ◐ LIKELY ACTIVE |
| UWUnited Wisconsin Grain Producers | Friesland | WI | Chemical Manufacturing325190 | 20-99 | ◐ LIKELY ACTIVE |
| UIUsg Interiors LLC | Walworth | WI | Nonmetallic Mineral Product Manufacturing327420 | 20-99 | ◐ LIKELY ACTIVE |
| VCValley Cabinet, INC | De Pere | WI | Furniture and Related Product Manufacturing337110 | 100-499 | ◐ LIKELY ACTIVE |
| VHVan Holten's | Waterloo | WI | Food Manufacturing311421 | 100-499 | ◐ LIKELY ACTIVE |
| VZVan Zeeland Manufacturing INC | Little Chute | WI | Machinery Manufacturing333612 | 20-99 | ◐ LIKELY ACTIVE |