A Princess of Mars: Illustrated (1917) is a science fantasy novel by Edgar Rice Burroughs, the first of his Barsoom series. It is also a seminal instance of the planetary romance, a sub-genre of science fantasy that became highly popular in the decades following its publication. Its early chapters also contain elements of the Western.

The story is set on Mars, imagined as a dying planet with a harsh desert environment. Forty-three million miles from the earth--a succession of the weirdestand most astounding adventures in fiction. John Carter, American, findshimself on the planet Mars, battling for a beautiful woman, with theGreen Men of Mars, terrible creatures fifteen feet high, mounted onhorses like dragons.

The Barsoom series inspired a number of well-known 20th century science fiction writers, including Ray Bradbury, Arthur C. Clarke, Robert A. Heinlein, including Carl Sagan, who read A Princess of Mars when he was a child..