| T. Rowe Price | business, enterprise, public company | Baltimore | 1937 |
| Tablet | podcast production company, online magazine | Manhattan | June 2009 |
| TalonSoft | video game publisher, video game developer | Baltimore | 1995 |
| Tandy Corporation | video game publisher, trading company | Fort Worth | 1919 |
| Target Corporation | supermarket chain, company, public company | Minneapolis | June 24, 1902 |
| Tarleton State University | public educational institution of the United States, university | — | 1896 |
| TASCAM | business | Tokyo | 1971 |
| TaylorMade Golf Company | business | Carlsbad | 1979 |
| Tektronix | business | Beaverton | 1946 |
| Teledyne FLIR | business | Wilsonville | 1978 |
| Telltale Games | video game publisher, video game developer, business, independent business, enterprise | San Rafael | July 2004 |
| Tengen | video game publisher, video game developer | Milpitas | 1987 |
| Teradyne | business, public company | North Reading | 1960 |
| Tesla Energy | corporation, brand, organization, business, company | Fremont | — |
| Texas A&M University | public educational institution of the United States, United States senior military college, land-grant university, public research university | College Station | 1876 |
| Texas A&M University System | state university system | — | 1948 |
| Texas Christian University | church college, private not-for-profit educational institution, Christian school, private university | Fort Worth | 1873 |
| Texas Tech University | public educational institution of the United States, public research university | — | 1923 |
| Textron | conglomerate, public company | Rhode Island, Providence | 1923 |
| Thanhouser Company | film studio | New Rochelle | 1909 |
| The Asylum | film production company, film distributor, film studio | Hollywood, Los Angeles | 1997 |
| The Athletic | online newspaper, podcast network, business, sports journalism | San Francisco | January 2016 |
| The Bank of New York Mellon | business, enterprise | New York City | 2007 |
| The Beverly Hilton | hotel | — | 1955 |
| The Biltmore Los Angeles | hotel | — | 1923 |
| The Bitter End | concert hall, café, nightclub | — | 1961 |
| The Catholic University of America | Catholic university | — | 1887 |
| The Cheesecake Factory | restaurant chain, public company | Calabasas | 1978 |
| The Cigna Group | business, enterprise, public company | Bloomfield | 1982 |
| The Citadel | United States senior military college | — | 1842 |
| The Earth Institute | academic department, research institute, business | New York City | 1995 |
| The Fletcher School of Law and Diplomacy | law school, university | Medford | 1933 |
| The French Laundry | restaurant | — | 1900 |
| The Gillette Company | business, defunct organization, enterprise, public company | — | September 28, 1901 |
| The Halal Guys | restaurant, restaurant chain, fast casual restaurant | — | 1990 |
| The Hoover Company | business, subsidiary company | North Canton | 1908 |
| The Leading Hotels of the World | business | New York City | 1928 |
| The Linq | casino, hotel | — | 2014 |
| The McClatchy Company | publishing house, business, public company | Sacramento | 1857 |
| The Metropolitan Opera | production company, opera company, organization | Metropolitan Opera House | 1880 |
| The MIT Press | book publisher, open-access publisher, university press, academic publisher | Cambridge | 1932 |
| The New School | research university, private not-for-profit educational institution, educational institution, open-access publisher, private university | — | 1919 |
| The New Yorker | news magazine, publishing house, website, magazine, production team | New York City | February 21, 1925 |
| The Onion | monthly newspaper, weekly newspaper, business | Chicago | 1988 |
| The Pierre | hotel | — | 1930 |
| The Rockefeller University | biological research institute, private not-for-profit educational institution, private university | New York City | 1901 |
| The Signature at MGM Grand | skyscraper, condo hotel | — | 2006 |
| The Spaceship Company | business | Mojave | 2005 |
| The Stone Quarry | business | Pasadena | 2004 |
| The Travelers Companies | business, enterprise, public company | New York City | 1853 |
| The Trump Organization | business, enterprise | Trump Tower | 1923 |
| The University of Texas MD Anderson Cancer Center | hospital, public educational institution of the United States, university | Houston | 1941 |
| The Vanderpump Hotel Las Vegas | hotel | — | March 2, 1979 |
| The Viper Room | pub, business, nightclub, music venue | California | 1993 |
| The Wharton School | business school, private university | Philadelphia | 1881 |
| Theodore Roosevelt Island | river island, plantation, National Memorial of the United States | — | May 21, 1932 |
| Thermos L.L.C. | manufacturing company | Chicago, Minato | 1980 |
| ThinkFilm | film industry, film production company, film distributor | New York City | September 2001 |
| Thinking Machines Corporation | business, enterprise | Carter's Ink Building | 1983 |
| Thinking Machines Lab | business | — | 2025 |
| Thiokol | business, defunct organization | Trenton, Brigham City | 1929 |
| Thomas Jefferson University | private not-for-profit educational institution, university | Philadelphia | 1824 |
| THQ | video game publisher, video game developer, public company | Agoura Hills, California | 1990 |
| Thrustmaster | business | Hillsboro | 1990 |
| THX | technical standard, business | San Rafael | 1983 |
| Tiffany & Co. | jewelry shop chain, business, public company | New York City | 1837 |
| Tiger Electronics | business, subsidiary company | Vernon Hills | 1978 |
| Tiger of Sweden | business, brick and mortar | Stockholm | 1903 |
| Tilted Mill Entertainment | video game developer | Framingham | 2001 |
| Timely Comics | comics publishing company, business | Manhattan | 1939 |
| TiVo Corporation | business, enterprise, public company | Santa Clara, San Jose | 1983 |
| TJX Companies | business, enterprise, public company | Framingham | 1956 |
| TNT | production company, specialty channel, subscription television | Atlanta | October 3, 1988 |
| TopCoder | business, enterprise | San Francisco | 2001 |
| Touchstone Pictures | film production company | Burbank | February 15, 1984 |
| Towson University | public educational institution of the United States, university | — | 1866 |
| Toys "R" Us | toy store chain, baby goods shop, clothing store chain | Wayne | 1948 |
| Toys for Bob | video game developer | Novato | 1989 |
| Trans States Airlines | airline | United States, Bridgeton | 1985 |
| Trans World Airlines | airline | Fort Worth | 1926 |
| Treasure Island Hotel and Casino | skyscraper, casino, hotel | — | 1993 |
| Trek Bicycle Corporation | bicycle manufacturer, business | Waterloo | 1976 |
| Triangle Film Corporation | film production company, film studio | Culver City | July 11, 1915 |
| TriBeCa Productions | television production company, film production company | New York City | 1989 |
| Trident Microsystems | business, enterprise, public company | Santa Clara | 1987 |
| Trilith Studios | film studio, studio | Fayette County | 2014 |
| Trimark Pictures | film production company, business | Santa Monica | 1985 |
| Trimble | business, enterprise, public company | Westminster | 1978 |
| Trinity Washington University | private not-for-profit educational institution, university | Washington, D.C. | 1897 |
| Tripadvisor | travel website, website, business, enterprise, public company | Needham | February 14, 2000 |
| Tripwire Interactive | video game developer | Roswell | 2005 |
| TriStar Pictures | film production company | Culver City | 1982 |
| Troika Games | video game developer, organization | Irvine | 1998 |
| Troubadour | nightclub | — | 1957 |
| Trump International Hotel and Tower | skyscraper, hotel | — | 2009 |
| Trump Mobile | mobile virtual network operator, brand | — | June 16, 2025 |
| Trump Steaks | business | New York City | May 8, 2007 |
| TRW Inc. | business, enterprise | Euclid | 1901 |
| Turner Broadcasting System | production company, media company, business, enterprise | CNN Center | 1970 |
| Turner Construction | business | New York City | 1902 |
| Turner Entertainment | production company, business, talent agency | United States | August 4, 1986 |
| Turtle Beach Systems | business, public company | Valhalla | 1975 |
| Twentieth Century Pictures | film production company | Hollywood | June 26, 1933 |
| Twilio | website, business, company, public company | San Francisco | 2008 |
| Tyson Foods | business, enterprise, public company | Springdale | 1935 |