Nothing Underneath (Italian: Sotto il vestito niente) is a 1985 Italian thriller film directed by Carlo Vanzina. The film is about Bob Crane (Tom Schanley) who has visions of his fashion model twin sister (Nicola Perring) being murdered in Milan, but finds his sister has disappeared on his arrival in Italy.

Nothing Underneath was originally going to be developed by director Michelangelo Antonioni. After Antonioni dropped out, Carlo Vanzina and Enrico Vanzina were hired to work on the film, abandoning the novel the film was based on. Franco Ferrini was also hired and made further changes on Vanzina's story. The film was a great box office hit in Italy in 1985 leading to a sequel in the 1980s titled Too Beautiful to Die and a third film in 2011.