Thor Heyerdahl KStJ was a Norwegian adventurer and ethnographer with a background in biology with specialization in zoology, botany and geography.

Thor Vilhjálmsson was an Icelandic writer. He was born in Edinburgh, Scotland. Over the course of his life Vilhjálmsson wrote novels, plays, and poetry and also did translations. In 1988 he won the Nordic Council Literature Prize for his novel Justice Undone. In 1992, he won the Swedish Academy Nordic Prize, known as the 'little Nobel'.

Thorbjørn Egner was a Norwegian playwright, songwriter and illustrator known principally for his books, plays and musicals for children. He is principally associated with his narratives for children including Karius og Baktus (1949) and Folk og røvere i Kardemomme by (1955).

Thorkild Hansen was a Danish novelist most noted for his historical fiction. He is popularly known for his trilogy of novels about the Danish slave trade which is composed of Coast of Slaves (1967), Ships of Slaves (1968), and Islands of Slaves.

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.

Thornwell Jacobs was a professor, historian, author, fundraiser, university founder, and Presbyterian minister. He earned degrees from Presbyterian College in South Carolina and the Princeton Theological Seminary in New Jersey. He wrote The Law of White Circle, a novel about mulattos set during the Atlanta race massacre of 1906.

James Edwin Thorold Rogers, known as Thorold Rogers, was an English economist, historian and Liberal politician who sat in the House of Commons from 1880 to 1886. He deployed historical and statistical methods to analyse some of the key economic and social questions in Victorian England. As an advocate of free trade and social justice he distinguished himself from some others within the English Historical School.

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