US author of thrillers and some sf, who began publishing the latter with "First Man in a Satellite" for Super-Science Fiction in December 1958; sixteen further short sf/fantasy stories followed, chiefly for The Magazine of Fantasy and Science Fiction. His first sf novel Pig World (1971) depicts a Near-Future USA governed by a right-wing tyranny challenged by a vicious would-be demagogue. Soulmate (April 1970 F&SF; exp 1974) is a novel of possession (see Horror in SF), the victim being a young prostitute. I, Weapon (1974) features much violence and Sex involving Aliens. Runyon's sf tends to be action-filled, without extensive displacement or speculative content.
Runyon was one of several sf authors who ghosted paperback-original thrillers under the Ellery Queen byline.