| American Library Association | nonprofit organization, open-access publisher, professional association, library association, academic publisher | October 6, 1876 |
| Basecamp | business, enterprise | 2004 |
| Boeing | rail vehicle manufacturer, public company, aerospace manufacturer | 1934 |
| Chicago, Burlington and Quincy Railroad | railway company | 1856 |
| CME Group | stock exchange, business, enterprise, public company | July 12, 2007 |
| Continental Airlines | airline | 1934 |
| Drag City | independent record label | 1990 |
| Encyclopædia Britannica Inc. | book publisher, business | 1768 |
| Essanay Studios | film production company, film studio | 1907 |
| Exelon | holding company, business, enterprise, public company | 2000 |
| Feastables | business, company | April 2021 |
| GE HealthCare | business, medical device company, enterprise | 2004 |
| GE Transportation | business, enterprise | 1907 |
| Goose Island Brewery | brewery | 1988 |
| Groupon | business, public company | 2008 |
| Grubhub | food delivery, online service, business, subsidiary company, enterprise | 2004 |
| Illinois Institute of Technology | private not-for-profit educational institution, university | 1940 |
| Iron Galaxy Studios | video game publisher, video game developer | 2008 |
| Jones Lang LaSalle | business, enterprise, public company | 1783 |
| Kearney | business, enterprise | 1926 |
| Midway Games | video game developer, business, enterprise, public company | 1988 |
| Mondelez International | food manufacturer, business, chocolaterie, public company | 2012 |
| Morningstar, Inc. | financial services company, business, database, public company | 1984 |
| Motorola Solutions | organization, business, enterprise, public company | January 4, 2011 |
| Newberry Library | research library, nonprofit organization, rare book library | July 1, 1887 |
| Oscar Mayer | business | 1883 |
| Seeburg Corporation | business | 1902 |
| Shimmer Women Athletes | business, enterprise | November 6, 2005 |
| SRAM Corporation | bicycle part manufacturing company | 1987 |
| The Onion | monthly newspaper, weekly newspaper, business | 1988 |
| Thermos L.L.C. | manufacturing company | 1980 |
| United Airlines | holding company, airline, public company | April 6, 1926 |
| United Airlines Holdings | business, enterprise, public company | December 30, 1968 |
| University of Chicago Press | book publisher, university press | 1891 |
| Washburn Guitars | trademark, musical instrument manufacturing company, subsidiary company | 1883 |
| Wilson Sporting Goods | sporting goods manufacturer, organization, business | 1913 |
| Wrigley Company | business | April 1, 1891 |