He first came to semi-prominence as a cast member on the NBC sitcom Hearts Afire with John Ritter and Markie Post. His role as the villain in One False Move brought him to the attention of critics. He also had small roles in films like Indecent Proposal, On Deadly Ground, and Tombstone.
In 1996, he wrote, directed, and starred in an independent film titled Sling Blade, an expansion of a short film titled Some Folks Call It a Sling Blade. It is the story of Karl Childers, a mentally disadvantaged man. Sling Blade garnered international acclaim, won Thornton an Academy Award for his screenplay (as well as a nomination for his performance), and made him a star.
Thornton is a rare celebrity in that he has A-list status, but plays both leading-man roles and character roles. His southern, small-town persona has led him to be cast in a number of down-to-earth, "regular guy" parts. Even his role as the legendary Davy Crockett in 2003's The Alamo made an effort to demythologize the character and bring out his human foibles.