| American Library Association | nonprofit organization, open-access publisher, professional association, library association, academic publisher | October 6, 1876 |
| Bank One Corporation | business | 1863 |
| Boeing | rail vehicle manufacturer, public company, aerospace manufacturer | 1934 |
| Budget Rent a Car | business | 1958 |
| Chicago Public Schools | school district in the United States | — |
| Chicago, Burlington and Quincy Railroad | railway company | 1856 |
| CME Group | stock exchange, business, enterprise, public company | July 12, 2007 |
| DDB Worldwide | business | 1949 |
| Dr. Scholl's | brand, business | 1906 |
| Drag City | independent record label | 1990 |
| Exelon | holding company, business, enterprise, public company | 2000 |
| Federal Home Loan Banks | business, credit institution | 1932 |
| Gatorade | drink brand, trademark, business | 1965 |
| General American Transportation Corporation | business, enterprise, public company | 1933 |
| Goose Island Brewery | brewery | 1988 |
| Grubhub | food delivery, online service, business, subsidiary company, enterprise | 2004 |
| Haidilao | restaurant chain, business, company, public company | March 20, 1994 |
| Illinois Central Railroad | transport company | 1851 |
| Illinois Institute of Technology | private not-for-profit educational institution, university | 1940 |
| Iron Galaxy Studios | video game publisher, video game developer | 2008 |
| Kellanova | business, enterprise, public company | February 19, 1906 |
| MCA Inc. | media company, entertainment company, conglomerate, company, public company | November 10, 1958 |
| Moody Bible Institute | private not-for-profit educational institution, higher education institution, Bible college, Christian organization | 1886 |
| Motorola Solutions | organization, business, enterprise, public company | January 4, 2011 |
| NetherRealm Studios | video game developer | 2010 |
| Oscar Mayer | business | 1883 |
| Quaker Oats Company | business, enterprise | 1877 |
| Schwinn Bicycle Company | business | 1895 |
| The Onion | monthly newspaper, weekly newspaper, business | 1988 |
| The Willy Wonka Candy Company | food manufacturer, chocolaterie | 1971 |
| U.S. Cellular | business, enterprise, public company | 1983 |
| United Airlines | holding company, airline, public company | April 6, 1926 |
| United Express | brand, airline | 1985 |
| University of Chicago Law School | law school | 1902 |
| University of Chicago Press | book publisher, university press | 1891 |
| Wrigley Company | business | April 1, 1891 |