After having attended Texas A&M, Torn majored in animal husbandry at The University of Texas at Austin. Following graduation, Torn relocated from his native Texas to give Hollywood a shot, which meant pounding the pavement through auditions and supporting himself at another time. He made his debut in Baby Doll and appearances on television. Realizing that the way to success was a hard one, Torn headed to New York where he studied at the Actors Studio under Lee Strasberg and started becoming a prolific stage actor before moving back into television and film.

He has been a distinctive character actor in numerous films since then, often showing up well in roles like the rich, sleazy New Orleans blackmailer Slade opposite Steve McQueen and Karl Malden in 1965's The Cincinnati Kid. In 1972 he won rave reviews for his portrayal of a country & western singer in the low-key cult film Payday. He received what many felt was a long-overdue Academy Award nomination as Best Supporting Actor for his role in the 1983 film Cross Creek. For his scene-stealing supporting role as talk show producer Artie in The Larry Sanders Show, Torn received six consecutive Emmy award nominations as Best Supporting Actor in a Comedy Series and won the award once, in 1996. He also won an American Comedy Award for that role.

In 1988, he made a once-off, ill-received venture into directing with the unsuccessful Whoopi Goldberg comedy The Telephone.

Torn was married to actress Ann Wedgeworth from 1956 to 1961, whom he divorced to marry the Oscar-winning actress Geraldine Page. He and Page remained married until her death in 1987.