Don Juan DeMarco is a 1994 American romantic comedy-drama film starring Johnny Depp as John Arnold DeMarco, a man who believes himself to be Don Juan, the greatest lover in the world. Clad in a cape and domino mask, DeMarco undergoes psychiatric treatment with Marlon Brando's character, Dr. Jack Mickler, to cure him of his apparent delusion, but the psychiatric sessions have an unexpected effect on the psychiatric staff, some of whom find themselves inspired by DeMarco's delusion; the most profoundly affected is Dr. Mickler himself, who rekindles the romance in his complacent marriage.

The movie is based on two different sources; the modern-day story is based on director/screenwriter Jeremy Leven's short story "Don Juan DeMarco and the Centerfold" (the movie's original title before the studio changed it shortly before release), while the flashbacks depicting DeMarco's back-story are based on the more familiar legend of Don Juan, especially as told by Lord Byron in his version of the legend.

Depp received the London Film Critics Circle Award for Actor of the Year, along with his performance in Ed Wood, while the film's theme song, "Have You Ever Really Loved a Woman?", co-written and performed by Bryan Adams, was nominated for the Oscar, Grammy, and Golden Globe Award for Best Original Song.

John Arnold DeMarco is a 21-year-old who dresses like Zorro, with a mask, hat and cape, and claims to be Don Juan. After a passionate affair, he decides to commit suicide. At the site of the billboard of a masked model from which he plans to jump, psychiatrist Jack Mickler dissuades him by posing as Don Octavio de Flores. John is then held for a ten-day review in a mental institution.

Mickler, who is about to retire, insists on doing the evaluation and conducts it without medicating the youth. He listens to John's story as Don Octavio: Don Juan was born in Mexico, he has an affair with his school tutor which ultimately leads to the death of his father in a swordfight. Mickler listens to the story while spotting inconsistencies, such as his Castilian accent, but continues to go along with it.

At home, Mickler's marriage to his wife Marilyn lacks passion. As Mickler notices that John's presence at the institution is having an impact on the staff – both distracting the women and dancing with a male attendant on the lawn – he finds himself being influenced, and starts listening to opera in his house and rekindling the passion with Marilyn.

Eventually Mickler meets with John's grandmother, who tells him that John grew up in Phoenix, Arizona, and that his father, "The Dance King of Astoria", died in a car crash. When Mickler returns to the institution and confronts his patient with this information, John dismisses his grandmother as misanthropic and of making up the backstory.

In response Mickler recounts the story of an insecure young man who fell in love with a woman in a magazine, who then contacted her and was told she never wanted to speak to him again. When John asks what happened to the young man, Mickler tells him he tried to commit suicide.