| HIHanley Industries | Alton | IL | Fabricated Metal Product Manufacturing332993 | 20-99 | ◇ UNVERIFIED |
| HPHa Phillips & CO | Dekalb | IL | Machinery Manufacturing333415 | — | ◇ UNVERIFIED |
| HAHayes Abrasives INC | Hillsboro | IL | Nonmetallic Mineral Product Manufacturing327910 | 1-19 | ◇ UNVERIFIED |
| HPHenry Pratt CO | Aurora | IL | Fabricated Metal Product Manufacturing332900 | — | ◇ UNVERIFIED |
| HPHfr Precision Machining INC | Sugar Grove | IL | Fabricated Metal Product Manufacturing332710 | 20-99 | ◇ UNVERIFIED |
| HMH&m Machining | Machesney Park | IL | Fabricated Metal Product Manufacturing332618 | 20-99 | ◇ UNVERIFIED |
| HMHodgson Mill | Effingham | IL | Food Manufacturing311211 | — | ◇ UNVERIFIED |
| HIHoneywell International INC | Galena | IL | Computer and Electronic Product Manufacturing334419 | — | ◇ UNVERIFIED |
| IWIllini Wire Works INC | Olney | IL | Primary Metal Manufacturing331222 | 20-99 | ◇ UNVERIFIED |
| IMImperial Marble CORP | Somonauk | IL | Plastics and Rubber Products Manufacturing326191 | — | ◇ UNVERIFIED |
| ICIndustrial Coatings | Rock Falls | IL | Petroleum and Coal Products Manufacturing324122 | 1-19 | ◇ UNVERIFIED |
| IFIndustrial Fiber Glass INC | Melrose Park | IL | Plastics and Rubber Products Manufacturing326199 | 1-19 | ◇ UNVERIFIED |
| IIIntermatic INC | Spring Grove | IL | Machinery Manufacturing333514 | 100-499 | ◇ UNVERIFIED |
| IPInternational Paper CO | Rockford | IL | Paper Manufacturing322211 | — | ◇ UNVERIFIED |
| ISInternational Spring CO | Morton Grove | IL | Fabricated Metal Product Manufacturing332613 | 20-99 | ◇ UNVERIFIED |
| IDInterplex Daystar INC | Franklin Park | IL | Fabricated Metal Product Manufacturing332116 | — | ◇ UNVERIFIED |
| ISItw Shakeproof | Elk Grove Village | IL | Fabricated Metal Product Manufacturing332722 | — | ◇ UNVERIFIED |
| JCJc Custom Woodworking | Springfield | IL | Furniture and Related Product Manufacturing337212 | 1-19 | ◇ UNVERIFIED |
| KLKanzler Landscape Contractor INC | Volo | IL | Miscellaneous Manufacturing339999 | 1-19 | ◇ UNVERIFIED |
| KKKelly Kean Nissan | Oak Lawn | IL | Miscellaneous Manufacturing339999 | 20-99 | ◇ UNVERIFIED |
| KCKolorcure CORP | Batavia | IL | Chemical Manufacturing325910 | 1-19 | ◇ UNVERIFIED |
| LILang Ice CO | Chicago | IL | Beverage and Tobacco Product Manufacturing312113 | 20-99 | ◇ UNVERIFIED |
| LCLiquid Controls LLC | Lake Bluff | IL | Computer and Electronic Product Manufacturing334514 | — | ◇ UNVERIFIED |
| LILitho-type INC | Lansing | IL | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| LILmt INC | Galva | IL | Transportation Equipment Manufacturing336211 | 1-19 | ◇ UNVERIFIED |
| LALotton Art Glass | Crete | IL | Nonmetallic Mineral Product Manufacturing327212 | 1-19 | ◇ UNVERIFIED |
 Lsc Communications INC | Mattoon | IL | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| MAMacks Auto Recycling | Urbana | IL | Miscellaneous Manufacturing339999 | 1-19 | ◇ UNVERIFIED |
| MCMarathon Cutting Die, Formerly | Wheeling | IL | Fabricated Metal Product Manufacturing332813 | 20-99 | ◇ UNVERIFIED |
| MGMar Graphics | Valmeyer | IL | Printing and Related Support Activities323111 | 20-99 | ◇ UNVERIFIED |
| MMcfona | Geneva | IL | Food Manufacturing311930 | 100-499 | ◇ UNVERIFIED |
| MPMeda Pharmaceuticals INC | Decatur | IL | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| MIMedline INC. | Mundelein | IL | Plastics and Rubber Products Manufacturing326199 | — | ◇ UNVERIFIED |
| MPMenasha Packaging CO LLC | Edwardsville | IL | Paper Manufacturing322211 | — | ◇ UNVERIFIED |
| MGMertel Gravel CO | Peru | IL | Nonmetallic Mineral Product Manufacturing327320 | 20-99 | ◇ UNVERIFIED |
| MIMetalstamp INC | Channahon | IL | Fabricated Metal Product Manufacturing332116 | — | ◇ UNVERIFIED |
| MEMethode Electronics INC | Carthage | IL | Transportation Equipment Manufacturing336111 | — | ◇ UNVERIFIED |
| MMMicron Metal Finishing | Bridgeview | IL | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| MCMid Continent Fasteners INC | Rock Falls | IL | Miscellaneous Manufacturing339993 | 1-19 | ◇ UNVERIFIED |
| MCMid-illinois Concrete INC | Effingham | IL | Nonmetallic Mineral Product Manufacturing327320 | 20-99 | ◇ UNVERIFIED |
| MPMidland Products LLC | Tinley Park | IL | Chemical Manufacturing325612 | 1-19 | ◇ UNVERIFIED |
| MIMidwest Industrial Metals | Northlake | IL | Fabricated Metal Product Manufacturing332322 | 20-99 | ◇ UNVERIFIED |
| MLMidwest Laminating | Alsip | IL | Paper Manufacturing322130 | 1-19 | ◇ UNVERIFIED |
| MIMinnick Illinois LLC | Joliet | IL | Nonmetallic Mineral Product Manufacturing327390 | 20-99 | ◇ UNVERIFIED |
| MDModern Drop Forge CO | Blue Island | IL | Fabricated Metal Product Manufacturing332111 | 500+ | ◇ UNVERIFIED |
| MGMondelez Global LLC | Rockford | IL | Food Manufacturing311340 | — | ◇ UNVERIFIED |
| MSMorton Supplies INC | Morton | IL | Miscellaneous Manufacturing339999 | 1-19 | ◇ UNVERIFIED |
| MPM.o.w Printing INC. | Collinsville | IL | Printing and Related Support Activities323110 | 1-19 | ◇ UNVERIFIED |
| NMNational Metalwares L.p. | Aurora | IL | Primary Metal Manufacturing331210 | 100-499 | ◇ UNVERIFIED |
| NINavistar INC | Melrose Park | IL | Machinery Manufacturing333618 | — | ◇ UNVERIFIED |
