George Clayton Johnson (born July 10, 1929 in Cheyenne, Wyoming) is a science fiction writer most famous for co-writing the novel Logan's Run with William F. Nolan. He is also known for his work in television, writing screenplays for such noted series as The Twilight Zone, such as "Nothing in the Dark", "Kick the Can", and "A Game of Pool", and Star Trek, the first aired episode of the series, "The Man Trap". He also wrote the story on which the 1960 and 2001 films Ocean's Eleven were based and the novel on which the 1976 film Logan's Run was based.

He was proprietor of Cafe Frankenstein.

Born in a barn, he had to repeat the sixth grade and dropped out of school entirely in the eighth. He briefly served as a telegraph operator then draftsman in the Army, enrolled at the Alabama Polytechnic Institute (now Auburn University) under the G.I. Bill, quit to return to his travels around the U.S.A., working as an draftsman, before deciding he wanted to become a writer.
In 1960 the first story Johnson ever wrote served as the basis for the Rat Pack movie Ocean's Eleven, although most of the details were changed for the film. He joined a circle of Southern California science-fiction writers that included William F. Nolan, Charles Beaumont, Richard Matheson and Ray Bradbury. Through them he met Rod Serling, to whom he sold his first story ("All of Us Are Dying", produced as The Four of Us Are Dying) and, later, his first teleplay (A Penny for Your Thoughts).
"For me, fantasy must be about something, otherwise it's foolishness... ultimately it must be about human beings, it must be about the human condition, it must be another look at infinity, it must be another way of seeing the paradox of existence."
—George Clayton Johnson quoted in The Twilight Zone Companion