| Institute of Radio Engineers | — | 1912 |
| Instituto de la Tierra | Nueva York | 1995 |
| Instituto para la Información Científica | Filadelfia | 1960 |
| Intel | Santa Clara | 18 de julio de 1968 |
| International Flavors & Fragrances | Nueva York | 1958 |
| Interpublic Group of Companies | Nueva York | 1961 |
| Intersil | Milpitas | 1967 |
| Intuit | Mountain View | 1983 |
| Intuitive Machines | Houston | 2013 |
| Intuitive Surgical | Sunnyvale | 1995 |
| Invesco | Atlanta | 1935 |
| Invicta Fighting Championships | Enka | 2012 |
| Invicta Watch Group | Hollywood | 1837 |
| Ion Storm | Austin | 1996 |
| IRobot | Bedford | 1990 |
| Iron Crown Enterprises | Virginia | 1980 |
| ISDA | Nueva York | — |
| J. B. Hunt | Lowell | 1961 |
| J. C. Penney | Plano | 1902 |
| J. G. Brill Company | Filadelfia | 1868 |
| Jabil Circuit | San Petersburgo | 1966 |
| Jamba | Frisco | 1990 |
| Jasc Software | Eden Prairie | 1990 |
| JBL | Northridge | 1946 |
| Jeep | Toledo | 1941 |
| Jeppesen Sanderson | Inverness | 1934 |
| Jet | — | — |
| Jimmy John's | Champaign | 1983 |
| Johns Manville | Denver | 1858 |
| JP Morgan Chase | Nueva York | 1968 |
| K-R-I-T Motor Car Company | Detroit | 1909 |
| K-Swiss | Westlake Village | 1966 |
| Kaggle | San Francisco | abril 2010 |
| Kaiser Jeep | Toledo | 1953 |
| Kaltura | Nueva York, Nueva York | 2006 |
| Kaplan International Languages | Londres | 1967 |
| Kayak | Stamford | 2004 |
| Kel-Tec | Cocoa | 1991 |
| Kellanova | Chicago | 19 de febrero de 1906 |
| Kenner Products | Cincinnati | 1946 |
| Kingston Technology | Fountain Valley | 1987 |
| Kirby Company | Cleveland | 1914 |
| Kleiner Perkins Caufield & Byers | Menlo Park | 1972 |
| Kmart | Detroit | 1962 |
| Knight's Armament Company | Titusville | 1983 |
| Koch, Inc. | Wichita | 1940 |
| Kohl's | Menomonee Falls | 1962 |
| Kohlberg Kravis Roberts | Nueva York | 1976 |