| SFSchreiber Foods INC. Green Bay Plant | Green Bay | WI | Food Manufacturing311513 | — | ◇ UNVERIFIED |
| SMSemling Menke CO INC | Merrill | WI | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| SFSeneca Foods CORP | Cumberland | WI | Food Manufacturing311411 | — | ◇ UNVERIFIED |
| SFSeneca Foods CORP - Janesville Plant | Janesville | WI | Food Manufacturing311420 | — | ◇ UNVERIFIED |
| SFSeneca Foods Corporation - Gillett | Gillett | WI | Food Manufacturing311420 | — | ◇ UNVERIFIED |
| SISerigraph INC - Plant 3 | West Bend | WI | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| SISerigraph, INC. - Plant 4 | West Bend | WI | Printing and Related Support Activities323000 | — | ◇ UNVERIFIED |
| SISfi, INC. | Sparta | WI | Chemical Manufacturing325991 | — | ◇ UNVERIFIED |
| SIShanti Ind INC | Monticello | WI | Fabricated Metal Product Manufacturing332610 | — | ◇ UNVERIFIED |
| SISiemens Industry INC - Enviroscan | Rothschild | WI | Machinery Manufacturing333290 | — | ◇ UNVERIFIED |
| SCSierra Coating Technologies | De Pere | WI | Paper Manufacturing322220 | — | ◇ UNVERIFIED |
| SPSierra Pacific Windows | Merrill | WI | Wood Product Manufacturing321910 | — | ◇ UNVERIFIED |
| SPSierra Pacific Windows | Medford | WI | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| SSSierra Space | Middleton | WI | Transportation Equipment Manufacturing336415 | — | ◇ UNVERIFIED |
| SCSilgan Containers Manufacturing CORP | Kenosha | WI | Fabricated Metal Product Manufacturing332431 | — | ◇ UNVERIFIED |
| SCSilgan Containers Manufacturing Corporat | Waupun | WI | Fabricated Metal Product Manufacturing332430 | — | ◇ UNVERIFIED |
| SCSilgan Containers Mfg CORP | Oconomowoc | WI | Fabricated Metal Product Manufacturing332119 | — | ◇ UNVERIFIED |
| SJSimmons Juvenile Products CO | New London | WI | Furniture and Related Product Manufacturing337120 | — | ◇ UNVERIFIED |
| SMSimplicity Mfg INC | Port Washington | WI | Machinery Manufacturing333110 | — | ◇ UNVERIFIED |
| SCSiny CORP. | Janesville | WI | Textile Mills313241 | 100-499 | ◇ UNVERIFIED |
| SISkipperliner Industries | La Crosse | WI | Textile Mills313300 | — | ◇ UNVERIFIED |
| SKS K Williams CO | Milwaukee | WI | Fabricated Metal Product Manufacturing332810 | — | ◇ UNVERIFIED |
| SPSne-stevens Point | Stevens Point | WI | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| SPSolar Paints Varnish, Incorporated | Milwaukee | WI | Chemical Manufacturing325510 | — | ◇ UNVERIFIED |
 Sonoco Products CO | Wausau | WI | Fabricated Metal Product Manufacturing332110 | — | ◇ UNVERIFIED |
| SWSonoco Wisconsin Rapids Core Plant LLC | Wisconsin Rapids | WI | Paper Manufacturing322130 | — | ◇ UNVERIFIED |
| SISourcecut Industries, INC. | Osseo | WI | Wood Product Manufacturing321999 | 20-99 | ◇ UNVERIFIED |
| SMSparta Mfg CO INC | Sparta | WI | Primary Metal Manufacturing331510 | — | ◇ UNVERIFIED |
| SSSpecial Services Partners CORP | Neenah | WI | Paper Manufacturing322299 | — | ◇ UNVERIFIED |
| SMSpecialty Manufacturing of Menomonie, LLC | Boyceville | WI | Wood Product Manufacturing321920 | 20-99 | ◇ UNVERIFIED |
| SMSpecialty Minerals INC | Superior | WI | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
| SMSpecialty Minerals INC | Wisconsin Rapids | WI | Chemical Manufacturing325180 | — | ◇ UNVERIFIED |
| SWSprings Window Fashions LP | Wausau | WI | Furniture and Related Product Manufacturing337920 | — | ◇ UNVERIFIED |
| SLSpx Lindberg a Division of Spx Corporation | Watertown | WI | Fabricated Metal Product Manufacturing332811 | — | ◇ UNVERIFIED |
| STSsi Technologies INC (former) | Janesville | WI | Fabricated Metal Product Manufacturing332117 | — | ◇ UNVERIFIED |
| SSta-care | Pardeeville | WI | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| SPStark Pavement CORP | Milwaukee | WI | Petroleum and Coal Products Manufacturing324120 | — | ◇ UNVERIFIED |
| SBStock Building Supply | Green Bay | WI | Wood Product Manufacturing321990 | — | ◇ UNVERIFIED |
| SWStowe Woodward Company | Neenah | WI | Plastics and Rubber Products Manufacturing326290 | — | ◇ UNVERIFIED |
| SCStratatech CORP | Madison | WI | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| SDStroh Die Casting CO INC | Milwaukee | WI | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| SISuperior Industrial Coating INC | Racine | WI | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| SKSuperior Kiln | Mellen | WI | Wood Product Manufacturing321999 | — | ◇ UNVERIFIED |
| SSSuper Steel Products CORP | Milwaukee | WI | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| SZSussex Zinc Plating INC | Sussex | WI | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| SLSv Lab | Prescott | WI | Chemical Manufacturing325620 | — | ◇ UNVERIFIED |
| SISymet INC | Milwaukee | WI | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| SWSynergy Web Graphics | Mazomanie | WI | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| TCTankcraft CORP | Walworth | WI | Fabricated Metal Product Manufacturing332420 | — | ◇ UNVERIFIED |
| TSTarget Store T1895 | Milwaukee | WI | Machinery Manufacturing333120 | — | ◇ UNVERIFIED |
