| Jabil | business, enterprise, public company | St. Petersburg | 1966 |
| Jackson Guitars | business, musical instrument manufacturing company | Scottsdale | 1980 |
| Jacuzzi | business, company | Chino Hills | 1917 |
| Jakks Pacific | business, public company | Malibu | 1995 |
| James Madison University | public educational institution of the United States, public university | Harrisonburg | 1908 |
| Janet | airline | Las Vegas | 1972 |
| Jasc Software | business | Eden Prairie | 1990 |
| JBL | business | Northridge | 1946 |
| Jeep | car brand, business, enterprise, automobile manufacturer | Toledo | 1941 |
| Jet | brand, business, gas station chain | — | — |
| Jim Crockett Promotions | business | Charlotte | 1931 |
| John F. Kennedy School of Government | public policy school, graduate school, private school | Cambridge | 1936 |
| John Hancock Insurance | business | Boston | 1862 |
| Johnny Rockets | fast food restaurant chain, restaurant chain | Lake Forest | 1986 |
| Johns Hopkins University | private not-for-profit educational institution, research institute, open-access publisher, private university | Baltimore | 1876 |
| Johnson & Wales University, Providence | university | — | 1914 |
| JPMorgan Chase | global systemically important bank, bank, organization, business, enterprise, credit institution, public company | New York City | 1968 |
| Juniper Networks | business, enterprise, public company | Sunnyvale | February 6, 1996 |