X Minus One was a half-hour science fiction radio drama series broadcast from April 24, 1955 to January 9, 1958 in various timeslots on NBC.
Initially a revival of NBC's Dimension X (1950–51), the first 15 episodes of X Minus One were new versions of Dimension X episodes, but the remainder were adaptations by NBC staff writers, including Ernest Kinoy and George Lefferts, of newly published science fiction stories by leading writers in the field, including Isaac Asimov, Ray Bradbury, Philip K. Dick, Robert A. Heinlein, Frederik Pohl and Theodore Sturgeon, along with some original scripts by Kinoy and Lefferts.