| Take-Two Interactive | video game developer, public company | New York City | 1993 |
| TaylorMade Golf Company | business | Carlsbad | 1979 |
| Tazo | business | Portland | 1994 |
| Telarc International Corporation | record label, record company | Cleveland | 1977 |
| Teledyne FLIR | business | Wilsonville | 1978 |
| Teledyne Technologies | business, conglomerate, public company | Thousand Oaks | 1960 |
| Telltale Games | video game publisher, video game developer, business, independent business, enterprise | San Rafael | July 2004 |
| Temple University | public educational institution of the United States, collection, university | — | 1884 |
| Tengen | video game publisher, video game developer | Milpitas | 1987 |
| Tennessee State University | historically black college or university, public educational institution of the United States, school, land-grant university, public university | — | 1912 |
| Tennessee Technological University | public educational institution of the United States, public university | — | 1915 |
| Tennessee Valley Authority | electricity supply company, independent agency of the United States government, business | Knoxville | 1933 |
| Tesla Energy | corporation, brand, organization, business, company | Fremont | — |
| Texaco | brand, business, gas station chain, enterprise | San Ramon | 1901 |
| Texas Instruments | technology company, business, public company | Dallas | December 6, 1930 |
| The Athletic | online newspaper, podcast network, business, sports journalism | San Francisco | January 2016 |
| The Atlantic | news website, website, magazine, business | Washington, D.C. | 1857 |
| The Babylon Bee | satirical website, business | Jupiter | March 1, 2016 |
| The Beverly Hilton | hotel | — | 1955 |
| The Bitter End | concert hall, café, nightclub | — | 1961 |
| The Boring Company | business, transport company | Hawthorne | December 17, 2016 |
| The Cigna Group | business, enterprise, public company | Bloomfield | 1982 |
| The Citadel | United States senior military college | — | 1842 |
| The Coca-Cola Company | food manufacturer, holding company, public company | Atlanta | May 8, 1886 |
| The Collective | video game developer | Newport Beach | 1997 |
| The College of New Jersey | public educational institution of the United States, public university | — | 1855 |
| The Fletcher School of Law and Diplomacy | law school, university | Medford | 1933 |
| The Halal Guys | restaurant, restaurant chain, fast casual restaurant | — | 1990 |
| The Hertz Corporation | car rental company, business, enterprise, public company | Estero | 1918 |
| The Home Depot | hardware store chain, business, public company | Cobb County | 1978 |
| The Hoover Company | business, subsidiary company | North Canton | 1908 |
| The Jim Henson Company | business, enterprise | Hollywood | 1958 |
| The Kennedy/Marshall Company | business, enterprise | Santa Monica | 1992 |
| 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 Mosaic Company | business, public company | Plymouth | 2004 |
| The Muppets Studio | business | Los Angeles | 2004 |
| The New York Times Company | publishing house, business, enterprise, public company | New York Times Building, New York City | September 18, 1851 |
| The NPD Group | business, enterprise | Port Washington | 1967 |
| The Onion | monthly newspaper, weekly newspaper, business | Chicago | 1988 |
| The Public Theater | theatre company, nonprofit organization | New York City | 1954 |
| The Signature at MGM Grand | skyscraper, condo hotel | — | 2006 |
| The Sims Studio | video game developer | Redwood City | 2006 |
| The Spaceship Company | business | Mojave | 2005 |
| The Stone Quarry | business | Pasadena | 2004 |
| The Timberland Company | business, subsidiary company, enterprise, public company | Stratham | 1952 |
| The Trump Organization | business, enterprise | Trump Tower | 1923 |
| The Vanderpump Hotel Las Vegas | hotel | — | March 2, 1979 |
| The Vanguard Group | business, enterprise, company | Malvern | May 1, 1975 |
| The Viper Room | pub, business, nightclub, music venue | California | 1993 |
| The Walt Disney Company | film production company, media conglomerate, commercial organization, business, public company | Burbank | October 16, 1923 |
| The Willy Wonka Candy Company | food manufacturer, chocolaterie | Chicago | 1971 |
| Theodore Roosevelt Island | river island, plantation, National Memorial of the United States | — | May 21, 1932 |
| Theranos | enterprise, company | Palo Alto | 2003 |
| Thermo Fisher Scientific Inc. | business, enterprise, public company | Waltham | 2006 |
| Thomas Edison State University | public educational institution of the United States, school, academic institution | — | 1972 |
| 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 |
| TIAA | insurance company, business | New York City | 1918 |
| Tiger of Sweden | business, brick and mortar | Stockholm | 1903 |
| Tilted Mill Entertainment | video game developer | Framingham | 2001 |
| Time Warner Cable | internet service provider, production company, business, enterprise, public company | New York City | 1989 |
| Timex Group USA | business | Middlebury, United States | 1854 |
| Titan Media | pornography website, pornographic film studio | San Francisco | 1995 |
| TJX Companies | business, enterprise, public company | Framingham | 1956 |
| TKO Group Holdings | business, company | New York City | September 12, 2023 |
| Todd Haimes Theatre | Broadway theatre, theatre building, movie theater | — | October 2, 1918 |
| Todd-AO | cinema film format, trade name, business | Hollywood | 1953 |
| Toro | business, enterprise, public company | Bloomington | 1914 |
| Townsquare Media | media company, public company | Greenwich | 1996 |
| Towson University | public educational institution of the United States, university | — | 1866 |
| Toys for Bob | video game developer | Novato | 1989 |
| Tractor Supply Company | business, enterprise, public company | Brentwood | 1938 |
| Trans Executive Airlines | airline | Honolulu | 1982 |
| Travel + Leisure Co. | holding company, public company | Parsippany-Troy Hills | 1979 |
| Trek Bicycle Corporation | bicycle manufacturer, business | Waterloo | 1976 |
| TriBeCa Productions | television production company, film production company | New York City | 1989 |
| Trinity Broadcasting Network | production company, television network, nonprofit organization, business | Costa Mesa | 1973 |
| Trinity Evangelical Divinity School | university | — | 1950 |
| Tripadvisor | travel website, website, business, enterprise, public company | Needham | February 14, 2000 |
| Tripwire Interactive | video game developer | Roswell | 2005 |
| Troma Entertainment | film production company | New York City | 1974 |
| 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 |
| Trumpet Records | record label, business, company | — | 1951 |
| TRW Automotive | business, enterprise, public company | — | — |
| TRW Inc. | business, enterprise | Euclid | 1901 |
| TSG Entertainment | film production company, commercial organization | New York City | 2012 |
| Tumi Inc. | brand, business | Edison | 1975 |
| Tupperware | multi-level marketing company, brand, generic trademark, public company | Orlando | 1946 |
| Turn 10 Studios | video game developer | Redmond | 2001 |
| Turner Construction | business | New York City | 1902 |
| Turtle Beach Systems | business, public company | Valhalla | 1975 |
| Twentieth Century Pictures | film production company | Hollywood | June 26, 1933 |
| Twitter, Inc. | privately held company, public company | San Francisco | April 19, 2007 |