The Proteus Operation is a science fiction alternate history novel written by James P. Hogan. The plot focuses on an Anglo-American team of soldiers and civilians sent back in time from the Nazi-dominated world of 1975 to prevent an Axis victory in World War II that was engineered by more advanced time travelers from the 21st century.

James Patrick Hogan was a British science fiction author. His major works include the Giants series of five novels published between 1977 and 2005.