"Old Devil Moon" is a popular song composed by Burton Lane with lyrics by Yip Harburg for the 1947 musical Finian's Rainbow. It was introduced by Ella Logan and Donald Richards in the Broadway show. The song takes its title from a phrase in "Fun to Be Fooled", a song that Harburg wrote with Harold Arlen and Ira Gershwin for the 1934 musical Life Begins at 8:40.

In the 1968 film version, the song was performed by Don Francks and Petula Clark.