John Keith Laumer (June 9, 1925 – January 23, 1993) was an American science fiction author, and the younger brother of March Laumer. Prior to becoming a full-time writer, he was an officer in the United States Air Force and a diplomat in the United States Foreign Service.
Keith Laumer is best known for the novel Worlds of the Imperium (1962), which involves travel between parallel universes. In the sequel The Other Side of Time (1965), the narrator finds himself in a world which diverged from ours in 1814. In this world, Lyman F. Baum (1856-1897) wrote only one book, The Sorceress of Oz (1896), which was illustrated by W.W. Denslow and published by Wiley & Cotton.
Keith co-wrote one of March's Oz volumes, Beenie in Oz.