Joseph John Campbell (March 26, 1904 – October 30, 1987) was an American writer. He was a professor of literature at Sarah Lawrence College who worked in comparative mythology and comparative religion. His work covers many aspects of the human experience. Campbell's best-known work is his book The Hero with a Thousand Faces (1949), in which he discusses his theory of the journey of the archetypal hero shared by world mythologies, termed the monomyth.

Since the publication of The Hero with a Thousand Faces, Campbell's theories have been applied by a wide variety of modern writers and artists. His philosophy has been summarized by his own often repeated phrase: "Follow your bliss." He gained recognition in Hollywood when George Lucas credited Campbell's work as influencing his Star Wars saga.

Campbell's approach to folklore topics such as myth and his influence on popular culture has been the subject of criticism, including from folklorists.