Andrew Jefferson Offutt was an American science fiction and fantasy author. He wrote as Andrew J. Offutt, A.J. Offutt, and Andy Offut. His normal byline, andrew j. offutt, had his name in all lower-case letters. His son is the author Chris Offutt.

Offutt began publishing in 1954 with the story And Gone Tomorrow in If. Despite this early sale, he didn't consider his professional life to have begun until he sold the story Blacksword to Galaxy in 1959. His first novel was Evil Is Live Spelled Backwards in 1970.

Offutt published numerous novels and short stories, including many in the Thieves World series edited by Robert Lynn Asprin and Lynn Abbey, which featured his best known character, the thief Hanse, also known as Shadowspawn (and, later, Chance). His Iron Lords series likewise was popular. He also wrote two series of books based on characters by Robert E. Howard, one on Howard's best known character, Conan, and one on a lesser known character, Cormac mac Art.

As an editor Offutt produced a series of five anthologies entitled Swords Against Darkness, which included the first professional sale by Charles de Lint.

Offutt also wrote a large number of pornographic works under twelve different pseudonyms, not all of them identified. Those known include John Cleve, J.X. Williams, and Jeff Douglas. His main works in this area are the science fiction Spaceways series, most of whose volumes were written in collaboration, and the historical Crusader series.