Ghost in the Invisible Bikini is a 1966 American fantasy comedy film. It is the seventh and last of American International Pictures' beach party films. The film features the cast cavorting in and around a haunted house and the adjacent swimming pool.

Besides the usual bikini-clad cast, random singing, silly plot line, musical guests, and ridiculous chases and fight scenes, the continuity linking this to the other beach films is the Rat Pack motorcycle gang led by Eric Von Zipper (Harvey Lembeck), as well as the appearance of previous beach party alumni Tommy Kirk, Deborah Walley, Bobbi Shaw, Jesse White, Aron Kincaid, Quinn O'Hara and Boris Karloff.Pop singer Nancy Sinatra, who was on the rise at the time just before the film was released, has a supporting role and performs one song written for the film; and The Bobby Fuller Four appear as themselves and sing two songs. Claudia Martin, daughter of Dean Martin, co-stars in the film as Lulu. The Italian starlet Piccola Pupa appears as herself and sings a song.