|First appearance||The Godfather (novel)|
|Last appearance||The Godfather Part III|
|Created by||Mario Puzo|
|Portrayed by||Al Martino|
|Relatives||Vito Corleone (Godfather)|
John "Johnny" Fontane is a fictional character in Mario Puzo's novel The Godfather and the series of films based upon it. In Francis Ford Coppola's film adaptation of the novel, he was portrayed by Al Martino, the role having been turned down by Vic Damone.
Novel and film 
In the novel and film, Fontane is a famous crooner and occasional film star in the vein of Frank Sinatra. He is also the godson of Vito Corleone, the head of a major Mafia crime family. There are four occasions on which the Corleone family intervenes to help his career. The first, years before the main time frame of the original novel and film, is when Vito Corleone uses violent persuasion (an "offer he can't refuse") to buy out a contract that Fontane is locked into with a big band leader; after the bandleader turns down Vito Corleone's offer to buy out the contract, the Mafia chieftain orders his personal assassin Luca Brasi to put a gun to the man's forehead and says that, in one minute, either the man's signature or his brains will be on the contract.
The second, the infamous "horse-head" scene, is an act of intimidation, carried out at the Godfather's behest, to ensure Fontane receives a part in a war film. The film's producer, Jack Woltz, despises Fontane for "ruining" a woman he was sexually interested in, and thus blacklists him from the production. After Corleone family consigliere Tom Hagen fails to persuade Woltz to give Fontane the part, Brasi beheads Woltz's prize racehorse, Khartoum, and puts the animal's head in Woltz's bed as a warning. Terrified, Woltz relents and casts Fontane. Months later, Vito uses his Hollywood connections to ensure that Fontane wins the Academy Award for Best Actor (although the actual winner that year was Ray Milland for The Lost Weekend). Finally, the Corleones lend Fontane money to start his own film studio.
Fontane is a minor character in the movie adaptation. In the original novel, however, the character is far more central, with large portions of the book dedicated to his adventures and misadventures in Los Angeles and Las Vegas, Nevada, his precarious relationship with childhood friend and former partner Nino Valenti, and his struggles with losing the singing voice that made him famous. In the novel, Fontane develops (and eventually is cured of) lesions on his vocal cords.
Fontane was widely seen to have been based on Frank Sinatra, whose career was in a slump before being saved by his Academy Award-winning appearance in From Here to Eternity. While Puzo never made this claim, he also never denied it.
Novel sequels 
The character is expanded upon in the novel The Godfather Returns by Mark Winegardner. In the 2004 novel, he campaigns for the presidential election of his friend, James Kavanaugh "Jimmy" Shea, who is based on former President John F. Kennedy.
In Winegardner's sequel The Godfather's Revenge, Fontane becomes romantically involved with Francesca Corleone, daughter of Sonny. They are married at the end of the novel. In this novel, the real Sinatra is mentioned twice, even within a discussion between Fontane and Francesca.
Film casting 
According to Al Martino, he was cast in the film in a similar manner to Johnny Fontane. Martino claims that he used a connection to Mafia boss Russell Bufalino to intervene on his behalf and secure his role in the film.