Walter Michael Miller Jr. was an American science fiction writer. His fix-up novel, A Canticle for Leibowitz (1959), the only novel published in his lifetime, won the 1961 Hugo Award for Best Novel. Prior to its publication, he was a writer of short stories.

A Canticle for Leibowitz is a post-apocalyptic social science fiction novel by American writer Walter M. Miller Jr., first published in 1959. Set in a Catholic monastery in the desert of the southwestern United States after a devastating nuclear war, the book spans thousands of years as civilization rebuilds itself. The monks of the Albertian Order of Leibowitz preserve the surviving remnants of man's scientific knowledge until the world is again ready for it.