Thomas Wentworth Higginson was an American Unitarian minister, author, abolitionist, politician, and soldier. He was active in abolitionism in the United States during the 1840s and 1850s, identifying himself with disunion and militant abolitionism. He was a member of the Secret Six who supported John Brown. During the Civil War, he served as colonel of the 1st South Carolina Volunteers, the first federally authorized black regiment, from 1862 to 1864. Following the war, he wrote about his experiences with African American soldiers and devoted much of the rest of his life to fighting for the rights of freed people, women, and other disfranchised peoples. He is also remembered as a mentor to poet Emily Dickinson.

Thomas Woolner was an English sculptor and poet who was one of the founder-members of the Pre-Raphaelite Brotherhood. He was the only sculptor among the original members.

Sir Thomas Wyatt was a 16th-century English politician, ambassador, and lyric poet credited with introducing the sonnet to English literature. He was born at Allington Castle near Maidstone in Kent, though the family was originally from Yorkshire. His family adopted the Lancastrian side in the Wars of the Roses. His mother was Anne Skinner, and his father Henry, who had earlier been imprisoned and tortured by Richard III, had been a Privy Councillor of Henry VII and remained a trusted adviser when Henry VIII ascended the throne in 1509.

Thompson Buchanan was an American writer. While a journalist he began writing novels, and then turned to plays, with 1909's A Woman's Way starring Grace George being his first hit. He began writing for movies in 1916, and also wrote radio sketches.

James Thorne Smith, Jr. was an American writer of humorous supernatural fantasy fiction under the byline Thorne Smith. He is best known today for the two Topper novels, comic fantasy fiction involving sex, much drinking and ghosts. With racy illustrations, these sold millions of copies in the 1930s and were equally popular in paperbacks of the 1950s.

Thornton Waldo Burgess was an American conservationist and author of children's stories. He was sometimes known as the Bedtime Story-Man, after his newspaper column Bedtime Stories. By the time he retired, he had written more than 170 books and 15,000 stories for the daily newspaper column.

Thornton Niven Wilder was an American playwright and novelist. He won three Pulitzer Prizes — for the novel The Bridge of San Luis Rey and for the plays Our Town and The Skin of Our Teeth — and a U.S. National Book Award for the novel The Eighth Day.

Thorstein Bunde Veblen was an American economist and sociologist who, during his lifetime, emerged as a well-known critic of capitalism.

Thucydides was an Athenian historian and general. His History of the Peloponnesian War recounts the fifth-century BC war between Sparta and Athens until the year 411 BC. Thucydides has been dubbed the father of "scientific history" by those who accept his claims to have applied strict standards of impartiality and evidence-gathering and analysis of cause and effect, without reference to intervention by the gods, as outlined in his introduction to his work.

Albius Tibullus was a Latin poet and writer of elegies. His first and second books of poetry are extant; many other texts attributed to him are of questionable origins.