T
- Tan Aik Kah- TAN (Tegumental Angiomyxoma-Neurothekeoma) syndrome
- James Mourilyan Tanner — Tanner stage
- Tarik-ibn-Ziyad (from Arabic djebl al-Tarik or "mountain of Tarik") — Gibraltar
- Siegbert Tarrasch — Tarrasch Defense
- Abel Tasman — Tasmania, Tasman Sea, Tasman Region, Abel Tasman National Park, Tasman Bay
- J. R. D. Tata — founder, Tata
- Stéphanie Tatin and Caroline Tatin — Tarte Tatin
- Temujin (Genghis Khan) — Chinggis Khaan International Airport
- Maria Teresa, the Grand Duchess of Luxembourg — Maria Teresa cocktail
- Nikola Tesla — Tesla coil, tesla — unit of magnetic flux density
- Luisa Tetrazzini, operatic soprano — Chicken Tetrazzini
- Leon Theremin — Theremin
- Lou Thesz — "Lou Thesz punches," a professional wrestling maneuver involving using primarily your legs to tackle an opponent to the ground, then delivering a series of punches while straddling your opponent.
- August Thyssen - founder of Thyssen, ThyssenKrupp
- Christopher Titus — Titus, an Emmy nominated TV series broadcast on FOX from 2000–2002.
- Saint Thomas — São Tomé and Príncipe
- John T. Thompson — Thompson submachine gun
- Miloš Tichý — comet P/2000 U6 Tichý
- Johann Daniel Titius and Johann Elert Bode — Titius-Bode Law
- James Tobin — the proposed Tobin tax
- John Ronald Reuel Tolkien — Tolkien Estate, 2675 Tolkien, Tolkienology
- Howard Henry Tooth — Charcot-Marie-Tooth disease
- Carlos Torre Repetto — Torre Attack
- Evangelista Torricelli — torr, unit of pressure
- Linus Torvalds — Linus's law, Linux operating system (from Linus' Minix), Tux — mascot of Linux (from Torvald's Unix)
- Charles Townshend — Townshend Acts
- Sakichi Toyoda — founder, Toyota
- Trillian — Trillian (software), Project Trillian
- Octavio Trompowsky — Trompowsky Attack
- The Troubadour (London) founded 1954 - The Troubadour (Los Angeles) founded 1957
- Donald Trump — Trump Tower, the Trump International Hotel and Tower, Trump Plaza etc.
- Alan Turing — Turing machine, Turing-complete, Turing tarpit, Turing test, Church-Turing thesis, Church-Turing-Deutsch principle
- J. M. W. Turner, English painter — Turner Prize in art
- Ted Turner, media mogul — Turner Entertainment, Turner Classic Movies, Turner Broadcasting System or TBS, TBS Superstation, WTBS, Turner Network Television or TNT, Turner Tomorrow Fellowship Award, Ted Turner debate (a style of team debate recognized by the National Forensic League; also referred to as Controversy debate)
- Marie Tussaud — Madame Tussauds wax museum
Read more about this topic: List Of Eponyms (L-Z)