| MFMaster Food | Chicago | IL | Food Manufacturing311710 | — | ◐ LIKELY ACTIVE |
| MMauser | Chicago | IL | Fabricated Metal Product Manufacturing332439 | 20-99 | ◐ LIKELY ACTIVE |
| MPMauser Packaging Solutions | Chicago | IL | Paper Manufacturing322219 | 20-99 | ◐ LIKELY ACTIVE |
| MLMcCracken Label Co. | Chicago | IL | Printing and Related Support Activities323111 | 20-99 | ◐ LIKELY ACTIVE |
| MPMega Petroleum LLC | Chicago | IL | Petroleum and Coal Products Manufacturing324110 | — | ◐ LIKELY ACTIVE |
| MPMeitheal Pharmaceuticals, INC | Chicago | IL | Chemical Manufacturing325412 | — | ◐ LIKELY ACTIVE |
| MJMeridian Jetpack INC | Chicago | IL | Transportation Equipment Manufacturing336411 | — | ▲ REPORTED CLOSED |
| MWMeta Wine | Chicago | IL | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| MDMichael D Robinson and Associates, INC. | Chicago | IL | Miscellaneous Manufacturing339995 | — | ◐ LIKELY ACTIVE |
| MBmiddle brow beer & wine | Chicago | IL | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| MMMidwest Meadwerks | Chicago | IL | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| MSMidwest Smoked Meats, LLC | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| MHMonastery Hill Bindery | Chicago | IL | Leather and Allied Product Manufacturing316998 | 20-99 | ◐ LIKELY ACTIVE |
| MSMotorola Solutions Inc | Chicago | IL | Computer and Electronic Product Manufacturing334220 | 500+ | ◐ LIKELY ACTIVE |
| MCMpc Containment Systems LLC | Chicago | IL | Plastics and Rubber Products Manufacturing326299 | — | ◐ LIKELY ACTIVE |
| MMpp | Chicago | IL | Food Manufacturing311340 | 1-19 | ◐ LIKELY ACTIVE |
| MCMW - Cicero | Chicago | IL | Food Manufacturing311991 | 100-499 | ◐ LIKELY ACTIVE |
| NFNealey's Foods, Inc. | Chicago | IL | Food Manufacturing311615 | — | ◐ LIKELY ACTIVE |
| NBNeiman Brothers Company, Inc. | Chicago | IL | Food Manufacturing311999 | 20-99 | ◐ LIKELY ACTIVE |
| NLNepaley LLC | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| NHNew Hudson Facades - IL | Chicago | IL | Fabricated Metal Product Manufacturing332323 | 1-19 | ◐ LIKELY ACTIVE |
| NWNewly Weds Foods Headquarters | Chicago | IL | Food Manufacturing311824 | 100-499 | ◐ LIKELY ACTIVE |
| NSNew S.B.L., Inc. | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| NSNew Specialty Products, Inc. | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| NINita's in & Out Apparel INC | Chicago | IL | Apparel Manufacturing315990 | — | ◐ LIKELY ACTIVE |
| NMNorthwest Meat Company | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| NCNSA Chicago | Chicago | IL | Apparel Manufacturing315220 | 100-499 | ◐ LIKELY ACTIVE |
| OAO&k American - Chicago Plant | Chicago | IL | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| OYOmega Yeast Labs LLC | Chicago | IL | Food Manufacturing311999 | 20-99 | ◐ LIKELY ACTIVE |
| OROptivex Robotics, INC. | Chicago | IL | Miscellaneous Manufacturing339112 | — | ◐ LIKELY ACTIVE |
| OTOrd - T1 | Chicago | IL | Food Manufacturing311340 | 1-19 | ◐ LIKELY ACTIVE |
| OKOriental Kitchen Corp. | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| OFOscar's Foods | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| ODOttawa Dental Laboratory, LLC - Chicago Location | Chicago | IL | Miscellaneous Manufacturing339116 | 1-19 | ◐ LIKELY ACTIVE |
| PCPapa Charlie's | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| PSParagon Spring Company | Chicago | IL | Fabricated Metal Product Manufacturing332613 | — | ◐ LIKELY ACTIVE |
| PPPark Packing of Chicago | Chicago | IL | Food Manufacturing311611 | 20-99 | ◐ LIKELY ACTIVE |
| PPPeoria Packing, Ltd. | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| POPepe's Operating, LLC | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| PPershing | Chicago | IL | Food Manufacturing311991 | 20-99 | ◐ LIKELY ACTIVE |
| PWPioneer Wholesale Meat | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| PPregis -Corporate | Chicago | IL | Plastics and Rubber Products Manufacturing326150 | 100-499 | ◐ LIKELY ACTIVE |
| PLPrint Lounge INC the | Chicago | IL | Printing and Related Support Activities323113 | — | ◐ LIKELY ACTIVE |
| RFRamarc Foods, Inc. | Chicago | IL | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| RPRam Products LLC | Chicago | IL | Plastics and Rubber Products Manufacturing326199 | — | ◐ LIKELY ACTIVE |
| RRandolph | Chicago | IL | Food Manufacturing311340 | 1-19 | ◐ LIKELY ACTIVE |
| RCR C Industries INC | Chicago | IL | Fabricated Metal Product Manufacturing332813 | — | ▲ REPORTED CLOSED |
| RHRhine Hall | Chicago | IL | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| RMRi-del Manufacturing INC | Chicago | IL | Fabricated Metal Product Manufacturing332999 | — | ◐ LIKELY ACTIVE |
| RRockfon | Chicago | IL | Fabricated Metal Product Manufacturing332323 | 100-499 | ◐ LIKELY ACTIVE |