The Outlaws of Mars is a science fiction novel by Otis Adelbert Kline in the planetary romance subgenre pioneered by Edgar Rice Burroughs.

The novel is a semi-sequel to Kline's earlier Swordsman of Mars, as the setting is the same and the two books have some characters in common.

He starts out on the wrong foot, meeting a princess and killing the fearsome-looking Martian beast he takes to be menacing her, which actually turns out to be her pet.

Various adventures follow, with dazzling swordplay, feats of strength, and other trials, tribulations and treacheries.

Floyd C. Gale of Galaxy Science Fiction in 1961 rated the "old-fashioned fairy tale" three stars out of five [1]