| The Hertz Corporation | Estero | 1918 |
| The Home Depot | Cobb County | 1978 |
| The Hoover Company | North Canton | 1908 |
| The Jim Henson Company | Hollywood | 1958 |
| The Kennedy/Marshall Company | Santa Monica | 1992 |
| The McClatchy Company | Sacramento | 1857 |
| The Mosaic Company | Plymouth | 2004 |
| The Muppets Studio | Los Angeles | 2004 |
| The New York Times Company | New York Times Building, New York City | September 18, 1851 |
| The NPD Group | Port Washington | 1967 |
| The Onion | Chicago | 1988 |
| The Spaceship Company | Mojave | 2005 |
| The Stone Quarry | Pasadena | 2004 |
| The Timberland Company | Stratham | 1952 |
| The Trump Organization | Trump Tower | 1923 |
| The Vanguard Group | Malvern | May 1, 1975 |
| The Viper Room | California | 1993 |
| The Walt Disney Company | Burbank | October 16, 1923 |
| Thermo Fisher Scientific Inc. | Waltham | 2006 |
| TIAA | New York City | 1918 |
| Tiger of Sweden | Stockholm | 1903 |
| Time Warner Cable | New York City | 1989 |
| Timex Group USA | Middlebury, United States | 1854 |
| TJX Companies | Framingham | 1956 |
| TKO Group Holdings | New York City | September 12, 2023 |
| Todd-AO | Hollywood | 1953 |
| Toro | Bloomington | 1914 |
| Tractor Supply Company | Brentwood | 1938 |
| Trek Bicycle Corporation | Waterloo | 1976 |
| Trinity Broadcasting Network | Costa Mesa | 1973 |
| Tripadvisor | Needham | February 14, 2000 |
| Trump Steaks | New York City | May 8, 2007 |
| Trumpet Records | — | 1951 |
| TRW Automotive | — | — |
| TRW Inc. | Euclid | 1901 |
| Tumi Inc. | Edison | 1975 |
| Turner Construction | New York City | 1902 |
| Turtle Beach Systems | Valhalla | 1975 |
| U-Haul | Phoenix | 1945 |
| U.S. Bancorp | Minneapolis | 1850 |
| U.S. Cellular | Chicago | 1983 |
| U.S. Steel | Pittsburgh | 2001 |
| Ubiquiti | New York City | October 2003 |
| UGG | Goleta | 1978 |
| Ulta Beauty | Bolingbrook | 1990 |
| Union Carbide | Danbury | 1957 |
| Union Iron Works | San Francisco | 1849 |
| United Press International | Washington, D.C. | 1907 |