Lyon Sprague de Camp (November 27, 1907 – November 6, 2000) — known as L. Sprague de Camp — was an American writer of science fiction, fantasy, non-fiction and biography. In a career spanning 60 years, he wrote over 100 books, including novels and works of non-fiction, including biographies of other fantasy authors. He was a major figure in science fiction during the genre’s heyday in the 1930s and ’40s.

De Camp and Willy Ley won the 1953 International Fantasy Award for nonfiction recognizing their study of geographical myths, Lands Beyond (Rinehart, 1952). De Camp was a guest of honor at the 1966 World Science Fiction Convention and was named the third Gandalf Grand Master of Fantasy, after Tolkien and Fritz Leiber, at the 1976 convention. The Science Fiction Writers of America made him its fourth SFWA Grand Master in 1979 and he won the World Fantasy Award for Life Achievement in 1984, a Special Achievement Sidewise Award for Alternate History in 1996, citing “seminal works in the field,” and the Hugo Award for Nonfiction in 1997 for his autobiography, Time and Chance.