| American Library Association | nonprofit organization, open-access publisher, professional association, library association, academic publisher | October 6, 1876 |
| Amoco | oil company | 1889 |
| Art Institute of Chicago | nonprofit organization, educational institution, art museum | 1879 |
| Atchison, Topeka and Santa Fe Railway | railway company | 1895 |
| Boeing | rail vehicle manufacturer, public company, aerospace manufacturer | 1934 |
| Budget Rent a Car | business | 1958 |
| Chicago Board of Trade | futures exchange, business | 1848 |
| Chicago Mercantile Exchange | futures exchange, business | 1898 |
| Chicago, Rock Island and Pacific Railroad | railway company, business, transport company | 1866 |
| CosMc's | fast food restaurant | December 7, 2023 |
| DePaul University | private not-for-profit educational institution, university | 1898 |
| Drag City | independent record label | 1990 |
| Encyclopædia Britannica Inc. | book publisher, business | 1768 |
| Exelon | holding company, business, enterprise, public company | 2000 |
| Feastables | business, company | April 2021 |
| GE Transportation | business, enterprise | 1907 |
| General American Transportation Corporation | business, enterprise, public company | 1933 |
| Goose Island Brewery | brewery | 1988 |
| Guggenheim Partners | business | 1999 |
| Illinois Central Railroad | transport company | 1851 |
| Jones Lang LaSalle | business, enterprise, public company | 1783 |
| Lyric Opera of Chicago | nonprofit organization, opera company | 1954 |
| McDonald's | trademark, fast food restaurant chain, organization, business, public company | May 15, 1940 |
| Motorola Solutions | organization, business, enterprise, public company | January 4, 2011 |
| NetherRealm Studios | video game developer | 2010 |
| NIQ | business | 1923 |
| Northern Trust | business, financial institution, enterprise, credit institution, public company | 1889 |
| Quaker Oats Company | business, enterprise | 1877 |
| Schwinn Bicycle Company | business | 1895 |
| Shimmer Women Athletes | business, enterprise | November 6, 2005 |
| Skidmore, Owings and Merrill | architectural firm | 1936 |
| The Onion | monthly newspaper, weekly newspaper, business | 1988 |
| The Willy Wonka Candy Company | food manufacturer, chocolaterie | 1971 |
| Thermos L.L.C. | manufacturing company | 1980 |
| Tribune Publishing | publishing house | 2014 |
| U.S. Cellular | business, enterprise, public company | 1983 |
| United Airlines | holding company, airline, public company | April 6, 1926 |
| United Airlines Holdings | business, enterprise, public company | December 30, 1968 |
| United Express | brand, airline | 1985 |
| University of Chicago Law School | law school | 1902 |
| 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 |