"A Martian Odyssey" is a science fiction short story by Stanley G. Weinbaum originally published in the July 1934 issue of Wonder Stories. It was Weinbaum's second published story (in 1933 he had sold a romantic novel, The Lady Dances, to King Features Syndicate under the pseudonym Marge Stanley), and remains his best known. It was followed four months later by a sequel, "Valley of Dreams". These are the only stories by Weinbaum set on Mars.