Hiero's Journey is a post-apocalyptic science fiction novel by American writer Sterling Lanier first published in 1973 by Chilton Book Co.[1] The novel follows the adventures of a priest by the name of Per Hiero Desteen, a descendant of the ancient Métis people, as he explores the mutant-infested wilderness of Canada and North America five millennia after an event called The Death destroyed civilization (7476 A.D.).

Hiero's eventual allies include Gorm, a telepathic black bear, Luchare, a princess from the distant kingdom of D'alwah, and the Eleveners, followers of the Eleventh Commandment, "Thou shalt not destroy the Earth or the life thereon".

On his journey, Hiero faces many dangers, including mutated humans, mutant beasts, pirates, and the evil forces of The Brotherhood of the Unclean, ancient enemies of the Eleveners, who are desperate to learn the secret of Hiero's mission and stop him from undoing their evil plans.

[2] Several reviewers note that the novel reflects Cold War sensibilities, including fears of a nuclear holocaust wiping out civilization.

[5] The novel is also credited as a direct influence for another TSR roleplaying game, the post-apocalyptic RPG Gamma World.