Bad Santa is a 2003 American Christmas black comedy crime film directed by Terry Zwigoff, written by Glenn Ficarra and John Requa, and starring Billy Bob Thornton in the title role, with a supporting cast of Tony Cox, Lauren Graham, Brett Kelly, Lauren Tom, John Ritter, and Bernie Mac. It was Ritter's last live-action film appearance before his death on September 11, 2003. The film was dedicated to his memory. The Coen brothers are credited as executive producers. The film was released in North America on November 26, 2003, and was screened out of competition at the 2004 Cannes Film Festival. It received positive reviews and was a commercial success.

Black comedy, also known as dark comedy, morbid humor, gallows humor, black humor, or dark humor, is a style of comedy that makes light of subject matter that is generally considered taboo, particularly subjects that are normally considered serious or painful to discuss. Writers and comedians often use it as a tool for exploring vulgar issues by provoking discomfort, serious thought, and amusement for their audience. Thus, in fiction, for example, the term black comedy can also refer to a genre in which dark humor is a core component. Cartoonist Charles Addams was famous for such humor, e.g. depicting a boy decorating his bedroom with stolen warning signs including "NO DIVING – POOL EMPTY", "STOP – BRIDGE OUT" and "SPRING CONDEMNED."