Ghosts of Mars (titled onscreen as John Carpenter's Ghosts of Mars) is a 2001 American space Western action horror film written, directed and scored by John Carpenter. It was produced by Screen Gems and distributed by Sony Pictures Releasing. It stars Natasha Henstridge, Ice Cube, Jason Statham, Pam Grier, Clea DuVall and Joanna Cassidy. Set on a colonized Mars in the 22nd century, the film follows a squad of police officers and a convicted criminal who fight against the residents of a mining colony who have been possessed by the ghosts of the planet's original inhabitants.

Ghosts of Mars received mostly negative reviews and was a box office bomb, earning $14 million against a $28 million production budget. The film would be John Carpenter's last until his return with The Ward in 2010.

Ghosts of Mars has received a cult following since its release, with critics praising the action sequences, soundtrack and blending of genres. Given the film's debt to Western cinema, particularly the works of Howard Hawks, it has been considered by a number of critics as an example of the Weird Western subgenre.