Billy Bob Thornton (born August 4, 1955) is an American actor, filmmaker, singer, songwriter, and musician.

Thornton had his first break when he co-wrote and starred in the 1992 thriller One False Move, and received international attention after writing, directing, and starring in the independent drama film Sling Blade (1996), for which he won an Academy Award for Best Adapted Screenplay and was nominated for an Academy Award for Best Actor. He appeared in several major film roles in the 1990s following Sling Blade, including Oliver Stone's neo-noir U Turn (1997), political drama Primary Colors (1998), science fiction disaster film Armageddon (1998), the highest-grossing film of that year, and the crime drama A Simple Plan (1998), which earned him his third Oscar nomination.

In the 2000s, Thornton achieved further success in starring dramas Monster's Ball (2001), The Man Who Wasn't There (2001), and Friday Night Lights (2004); comedies Bandits (2001), Intolerable Cruelty (2003), and Bad Santa (2003); and action films Eagle Eye (2008) and Faster (2010). In 2014, Thornton starred as Lorne Malvo in the first season of the anthology series Fargo, earning a nomination for the Outstanding Lead Actor in a Miniseries or TV Movie at the Emmy Awards and won Best Actor in a Miniseries or TV Film at the 72nd Golden Globe Awards. In 2016, he starred in an Amazon original series, Goliath, which earned him a Golden Globe Award for Best Actor – Television Series Drama.

Thornton has been vocal about his distaste for celebrity culture, choosing to keep his life out of the public eye. However, the attention of the media has proven unavoidable in certain cases, his marriage to Angelina Jolie being a notable example. Thornton has written a variety of films, usually set in the Southern United States and mainly co-written with Tom Epperson, including A Family Thing (1996) and The Gift (2000). After Sling Blade, he directed several other films, including Daddy and Them (2001), All the Pretty Horses (2000), and Jayne Mansfield's Car (2012).

Thornton has received the President's Award from the Academy of Science Fiction, Fantasy & Horror Films, a Special Achievement Award from the National Board of Review, and a star on the Hollywood Walk of Fame. He has also been nominated for an Emmy Award, four Golden Globes, and three Screen Actors Guild Awards. In addition to film work, Thornton began a career as a singer-songwriter. He has released four solo albums and is the vocalist of the blues rock band The Boxmasters.