| Charlton Comics | Derby | 1945 |
| Charter Arms | Shelton | 1964 |
| Chicago Mercantile Exchange | Chicago | 1898 |
| Chicago, Rock Island and Pacific Railroad | Chicago | 1866 |
| Chikara | Filadelfia | 2002 |
| Chipotle Mexicano A La Parrilla | Denver, Newport Beach | 13 de julio de 1993 |
| Chips and Technologies | Milpitas | 1985 |
| Chiquita Brands International | Fort Lauderdale, Etoy | 30 de marzo de 1899 |
| Chobani | Norwich | 2005 |
| CHS Inc. | Inver Grove Heights | 1931 |
| Circuit City | Richmond | 1984 |
| Cirrus Logic | Austin | 1984 |
| Cisco Meraki | San Francisco | 2006 |
| Cisco Webex | Milpitas | 1995 |
| CIT Group Incorporated | Nueva York | 1908 |
| Citadel | Miami | 1990 |
| Citizens Financial Group | Providence | 1954 |
| Claris | Cupertino | 1987 |
| Clinique Laboratories, LLC | Nueva York | 1968 |
| Coach | Nueva York | 1941 |
| CodeGear | Scotts Valley, California | 2006 |
| Colorado Fuel and Iron | Colorado | — |
| Columbia Sportswear | Cedar Mill | 1938 |
| Commodore International | West Chester | 10 de octubre de 1958 |
| Comodo | Clifton | 1998 |
| Compañía Editora William B. Eerdmans | Grand Rapids | 1911 |
| Compañía Stepan | Northfield | 1932 |
| Comscore | Reston | 1999 |
| Concord Bicycle Music | Beverly Hills | 1973 |
| Conexant | Irvine | 1999 |
| Consol Energy | Pittsburgh | 1991 |
| Consolidated Aircraft | San Diego | 1923 |
| Constellation Brands | Victor | 1945 |
| Control Data Corporation | Bloomington | 1957 |
| Convergys | Cincinnati | 1998 |
| Cooper Tire & Rubber Company | Findlay | 1926 |
| Coors Brewing Company | Golden | 1873 |
| CoreWeave | Roseland | 2017 |
| Corporación Financiera de Regions | Birmingham | 13 de julio de 1971 |
| Corteva Agriscience | Washington D. C. | 15 de marzo de 2018 |
| Coty Inc. | Nueva York | 1904 |
| Crackle | Culver City | julio 2007 |
| Cricket Wireless | San Diego | 1999 |
| CrowdStrike | Austin | 29 de agosto de 2011 |
| Crunchbase | San Francisco | julio 2007 |
| Cummins Inc. | Columbus | 1919 |
| Currier & Ives | Nueva York | 1835 |
| CVS Health | Rhode Island, Woonsocket | 1963 |