| BEBodine Electric CO | Chicago | IL | Electrical Equipment, Appliance & Component Manufacturing335312 | — | ◇ UNVERIFIED |
| BBBody Builders Automotive INC | Rolling Meadows | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BTBodycote Thermal Processing | Melrose Park | IL | Fabricated Metal Product Manufacturing332811 | — | ◇ UNVERIFIED |
| BCBoeing CO | Mascoutah | IL | Transportation Equipment Manufacturing336411 | — | ◇ UNVERIFIED |
| BCBoeing Company | Chicago | IL | Transportation Equipment Manufacturing336411 | — | ◇ UNVERIFIED |
| BNBoge North America | Paris | IL | Plastics and Rubber Products Manufacturing326291 | — | ◇ UNVERIFIED |
| BSBolduc & Sons INC | Woodhull | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BRBombardier Recreational Products | Benton | IL | Transportation Equipment Manufacturing336612 | — | ◇ UNVERIFIED |
| BMBonell Manufacturing CO | Riverdale | IL | Machinery Manufacturing333516 | — | ◇ UNVERIFIED |
| BCBook Covers INC | Chicago | IL | Paper Manufacturing322130 | — | ◇ UNVERIFIED |
| BCBorden Chemical Forest Park Plant | Forest Park | IL | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| BTBorgwarner Transmission Systems | Frankfort | IL | Transportation Equipment Manufacturing336350 | — | ◇ UNVERIFIED |
| BCBose CORP | Danville | IL | Computer and Electronic Product Manufacturing334416 | — | ◇ UNVERIFIED |
| BDBoulder Designs | Rantoul | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BABpb America INC | Quincy | IL | Apparel Manufacturing315210 | — | ◇ UNVERIFIED |
| BCBrachs Confections INC | Chicago | IL | Food Manufacturing311330 | — | ◇ UNVERIFIED |
| BFBrad Foote Gear Works INC | Cicero | IL | Fabricated Metal Product Manufacturing332111 | — | ◇ UNVERIFIED |
| BIBradford Industries | Bradford | IL | Fabricated Metal Product Manufacturing332322 | — | ◇ UNVERIFIED |
| BCBradley Coatings | St Charles | IL | Fabricated Metal Product Manufacturing332722 | — | ◇ UNVERIFIED |
| BPBradley Printing Company | Des Plaines | IL | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| BMBrady Mccasland INC | East Saint Louis | IL | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
| BTBrahler's Truckers Supply INC | Jacksonville | IL | Plastics and Rubber Products Manufacturing326211 | — | ◇ UNVERIFIED |
| BPBrake Parts INC | Litchfield | IL | Transportation Equipment Manufacturing336340 | — | ◇ UNVERIFIED |
| BABrandis Aircraft | Taylorville | IL | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| BOBreckenridge of Il | Caseyville | IL | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| BOBreckenridge of Il | Lebanon | IL | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| BOBreckenridge of Il | Belleville | IL | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| BOBreckenridge of Illinois LLC | Hamel | IL | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| BMBrenntag Mid South INC | East St Louis | IL | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
| BMBretford Manufacturing INC | Schiller Park | IL | Machinery Manufacturing333514 | — | ◇ UNVERIFIED |
| BEBreuer Electric Mfg CO | Harwood Heights | IL | Machinery Manufacturing333911 | — | ◇ UNVERIFIED |
| BWBrian Wronke | Saint Joseph | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BLBridgeport Landings LLC | Chicago | IL | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
| BNBridgestone/firestone North America Tire LLC | Decatur | IL | Plastics and Rubber Products Manufacturing326211 | — | ◇ UNVERIFIED |
| BGBrightly Galvanized Products | Cicero | IL | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| BMBrite-o-matic Manufacturing INC | Arlington Heights | IL | Machinery Manufacturing333310 | — | ◇ UNVERIFIED |
| BBBrk Brands INC | Aurora | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BEBromley Excavating | Centralia | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| BPBrownies Polishing Shop | Ringwood | IL | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| BOBruce Oakley INC | Ottawa | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BOBruce Offset CO / Pearson I INC | Elk Grove Village | IL | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| BABrunner and Lay INC | Franklin Park | IL | Machinery Manufacturing333120 | — | ◇ UNVERIFIED |
| BBBrunswick Bicycles | Olney | IL | Transportation Equipment Manufacturing336991 | — | ◇ UNVERIFIED |
| BLBrunswick Laboratories INC | Murphysboro | IL | Food Manufacturing311999 | — | ◇ UNVERIFIED |
| BTB & T Polishing INC | Chicago | IL | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| BCBuchi CORP | Vernon Hills | IL | Computer and Electronic Product Manufacturing334516 | — | ◇ UNVERIFIED |
| BBBuckeye Barnett Station | Litchfield | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BBBuehler Buy Low # 443 | Fairfield | IL | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| BGBuffalo Grove Village of Public Svc Ctr | Buffalo Grove | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BABuilders Asphalt LLC | Elburn | IL | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
