''Watermelon Man'' is a 1970 American comedy-drama film directed by Melvin Van Peebles. Written by Herman Raucher, it stars Godfrey Cambridge (a pioneering black standup comic) as Jeff Gerber, an obnoxious and bigoted white insurance salesman who wakes up one morning to find that he has become black. The premise for the film was inspired by Franz Kafka's ''Literature/TheMetamorphosis'' and John Howard Griffin's autobiographical ''BlackLikeMe''.

Van Peebles' only studio film, ''Watermelon Man'' was a financial success, but Van Peebles did not accept Columbia Pictures' three-picture contract, as he knew that no one was going to finance his following film: ''Film/SweetSweetbacksBaadasssssSong''. The music for Watermelon Man, written and performed by Van Peebles, was released on a soundtrack album, which spawned the single "Love, that's America". In 2011, that single received much mainstream attention when videos set to the song and featuring footage of Occupy Wall Street became viral.

!!This film provides examples of:

* AngryBlackMan: Gerber has become this at the end of his film, disaffected with the system and training to defend himself by force.
* BlackFace: Inverted. Originally, the film producers wanted a white man who'd be made up as a black man for the rest of the film. Instead Peebles managed to convince them to cast Godfrey Cambridge, who was made up as a white man for the first section of the film.
* BlackIsBiggerInBed: Joked with twice in the film, both times with Gerber muttering that it's "an old wives' tale".
* BringingRunningShoesToACarChase: Jeff's morning workout is running along with a bus on the way to work (instead of just taking the bus). After he turns black he gets stopped by the cops for Running While Black. They assume he stole something - why else would he be running?
* ColorMeBlack: The basic premise of the movie.
* DownerEnding: Jeff's family and friends end up disowning him, feeling clearly ashamed of him at best, and despising him at worst.
* EthnicMenialLabor: When asked what he's paid for doing the menial work, Gerber makes the quip [[http://www.snopes.com/racial/mistaken/gardener.asp often attributed to Bill Cosby, et al]] that "The lady of the house lets me sleep with her". He also namechecks Chinese launderers when accusing his wife of having Chinese heritage.
* KarmicTransformation: Gerber is turned into the race that he hates.
** Subverted with Gerber's wife Althea, who at the start of the movie supported black civil rights. After Jeff's transformation, Althea snaps and calls on her right to refuse a black husband and after she leaves him, it is implied Althea is now searching for a white man.
* WhereDaWhiteWomenAt: Averted regarding Gerber and his wife. Played straight with the Norwegian secretary, who wants Gerber because he's black.