Past Master is a novel by science fiction writer R. A. Lafferty first published in 1968. The novel follows the attempt of a future Utopion society in preventing its decline, by bringing Sir Thomas More to the year 2535. The novel was well received by critics, and was nominated for the 1968 Nebula Award and the 1969 Hugo Award. It is generally categorized as part of the New Wave of science fiction.