Bill is the fictional titular character and the main antagonist of the film Kill Bill directed by Quentin Tarantino. He was portrayed by the late David Carradine. In the film, he is the leader of the Deadly Viper Assassination Squad, which included his brother, Budd (Michael Madsen). Bill's codename is Snake Charmer. At some point, he became the student of legendary swordsmith Hattori Hanzō (Sonny Chiba) and kung fu master Pai Mei (Gordon Liu).

For his performance, Carradine won the Saturn Award for Best Supporting Actor (the final award of his life) and was nominated for a Golden Globe.