| Hurricane Electric | Fremont | 1994 |
| IAC | Nova Iorque | 28 de julho de 1986 |
| Id Software | Richardson | 1 de fevereiro de 1991 |
| IGN | São Francisco | 29 de setembro de 1996 |
| Illinois Tool Works | Glenview | 1912 |
| Illumina | San Diego | 1998 |
| Imation | Oakdale | 1996 |
| Imgur | São Francisco | 2009 |
| Immediate Music | Santa Mônica | 1993 |
| Impossible Foods | Redwood City | 2011 |
| In-Q-Tel | condado de Arlington | 1999 |
| Indeed.com | Austin | novembro 2004 |
| IndyMac | Pasadena | 16 de julho de 1985 |
| Inflection IA | Palo Alto | 2022 |
| InnoCentive | Waltham | 2001 |
| Inovio Pharmaceuticals | Plymouth Meeting | 1983 |
| Institute for Scientific Information | Filadélfia | 1960 |
| Intel | Santa Clara | 18 de julho de 1968 |
| Interborough Rapid Transit Company | Nova Iorque | 1904 |
| International Flavors & Fragrances | Nova Iorque | 1958 |
| International Harvester | Chicago | 1902 |
| Invesco | Atlanta | 1935 |
| Invitrogen | Carlsbad | 1987 |
| Iomega | San Diego | 1980 |
| IQVIA Holdings, Inc. | Danbury, Durham | 2016 |
| Iridium | McLean | 2001 |
| IRobot | Bedford | 1990 |
| IShares | São Francisco | 2000 |
| Ithaca Gun Company | Upper Sandusky | 1880 |
| J. C. Penney | Plano | 1902 |
| J.Crew | 225 Liberty Street | 1983 |
| Jabil | São Petersburgo | 1966 |
| Jakks Pacific | Malibu | 1995 |
| Jelly Belly Candy Company | Fairfield | 1898 |
| Jeppesen | Inverness | 1934 |
| Jet | — | — |
| Jimmy John's | Champaign | 1983 |
| John Hancock Insurance | Boston | 1862 |
| Johns-Manville | Denver | 1858 |
| Juul | São Francisco | julho 2017 |
| K-Swiss | Westlake Village | 1966 |
| Kaggle | São Francisco | abril 2010 |
| Keds | Rockford | 1916 |
| Kellanova | Chicago | 19 de fevereiro de 1906 |
| Kelvinator | — | 1914 |
| Kenner Products | Cincinnati | 1946 |
| KeyBank | Cleveland | 1825 |
| Kimberly-Clark | Irving | 1928 |