(at around 46 mins) Otis' line "I am The Devil and I am here to do the Devil's work" is a slightly altered version of a quote spoken by Manson Family member Charles 'Tex' Watson during the infamous Tate Murders.
Rob Zombie stated in an interview that, up until 31 (2016), 'The Devil's Rejects' was probably the hardest film of his to cut down in order to receive an R rating.
Karen Black demanded a higher salary to reprise her role as Mother Firefly. Director Rob Zombie could not afford to increase her pay and decided to replace her with veteran actress Leslie Easterbrook.
Chris Jericho auditioned for the role of Rondo, but was told he was "too pretty" for the part. Danny Trejo was cast instead.
Sheri Moon Zombie's brother has a cameo as a police officer in the opening shootout scene. He was originally only on the set as a visitor, but director Rob Zombie put him in the scene because he knew how to handle firearms well.