Knight was born in Baker, Oregon in 1922, and grew up in Hood River, Oregon. He entered science-fiction fandom at the age of eleven and published two issues of a fanzine entitled Snide.
Knight's first professional sale was a cartoon drawing to a science-fiction magazine, Amazing Stories. His first story, "The Itching Hour," appeared in the Summer 1940 number of Futuria Fantasia, edited and published by Ray Bradbury. "Resilience" followed in the February 1941 number of Stirring Science Stories, edited by Donald Wollheim. An editorial error made the latter story's ending incomprehensible; it was reprinted in a 1978 magazine in four pages with a two-page introduction by Knight.
At the time of his first story sale, he was living in New York, and was a member of the Futurians. One of his short stories describes paranormal disruption of a science fiction fan group, and contains cameo appearances of various Futurians and others under thinly-disguised names: for instance, non-Futurian SF writer H. Beam Piper is identified as "H. Dreyne Fifer".
Knight's forte was the short story; he is widely acknowledged as having been a master of the genre. To the general public, he is best known as the author of "To Serve Man", a 1950 short story adapted for The Twilight Zone. It won a 50-year Retro Hugo in 2001 as the best short story of 1950. Knight also became well known as a science fiction critic, a career which began when he wrote in 1945 that A. E. van Vogt "is not a giant as often maintained. He's only a pygmy who has learned to operate an overgrown typewriter." He ceased reviewing when Fantasy & Science Fiction refused to publish a review. These reviews were later collected in In Search of Wonder.
Algis Budrys wrote that Knight and William Atheling Jr. (James Blish) had "transformed the reviewer's trade in the field", in Knight's case "without the guidance of his own prior example". The term "idiot plot", a story that only functions because almost everyone in it is an idiot, became well-known through Knight's frequent use of it in his reviews, though he believed the term was probably invented by Blish. Knight's only non-Retro Hugo Award was for "Best Reviewer" in 1956.
^Futurians Chester Cohen and Knight used the name Conanight jointly for two 1942 illustrations. Knight wrote three 1943–1944 short stories as Stuart Fleming.
^ abcdDamon Knight at the Internet Speculative Fiction Database (ISFDB). Retrieved 2013-04-04. Select a title to see its linked publication history and general information. Select a particular edition (title) for more data at that level, such as a front cover image or linked contents.
^ abStanyard, Dimensions Behind the Twilight Zone, p. 51.