| J. G. Brill Company | business, enterprise | Philadelphia | 1868 |
| Jack Daniel's | distillery, business, enterprise | Jack Daniel's Distillery | 1866 |
| Jacksonville State University | public educational institution of the United States, university | — | 1883 |
| Jacobs Engineering Group | business, enterprise, public company | Harwood Center | 1947 |
| Jakks Pacific | business, public company | Malibu | 1995 |
| Jamba | restaurant chain, business, public company | Frisco | 1990 |
| JanSport | brand, business | San Leandro | 1967 |
| Jasc Software | business | Eden Prairie | 1990 |
| JBL | business | Northridge | 1946 |
| Jeep | car brand, business, enterprise, automobile manufacturer | Toledo | 1941 |
| Jelly Belly | business | Fairfield | 1898 |
| Jet | brand, business, gas station chain | — | — |
| Jewish Publication Society | book publisher, publishing house | Philadelphia | June 3, 1888 |
| Jewish Telegraphic Agency | Jewish organization, news agency, bulletin | New York City | 1917 |
| Jimmy Carter Library and Museum | museum, library | — | 1986 |
| Jimmy John's | restaurant chain, business | Champaign | 1983 |
| John Carroll University | Jesuit university, private not-for-profit educational institution | — | 1886 |
| John F. Kennedy Presidential Library and Museum | museum, library | — | 1979 |
| John F. Kennedy School of Government | public policy school, graduate school, private school | Cambridge | 1936 |
| John Hancock Insurance | business | Boston | 1862 |
| Johns Hopkins School of Medicine | medical school | — | 1893 |
| Johns Hopkins University | private not-for-profit educational institution, research institute, open-access publisher, private university | Baltimore | 1876 |
| Johnson & Wales University, Providence | university | — | 1914 |
| Jones Lang LaSalle | business, enterprise, public company | Chicago, Aon Center | 1783 |
| Juilliard School | conservatory, drama school, private not-for-profit educational institution | New York City | 1905 |
| Juul | business | San Francisco | July 2017 |