The character of Squall Leonhart is believed to have been based on three notable people. Below is a brief description and picture of each.
Gackt Camui
Gack is a talented Japanese rocker, well-known for his time in the band Malice Mizer. He has never enclosed his real name or birthday to the public, however it is believed that he was born on July 4th, 1974 in Okinawa, Japan. Over the years, he has released countless albums, singles, VHSs, and DVDs, as well as performing in several other media, such films, commercials and games. Most notable of these are his role in the hit movie Moon Child (which he co-wrote with HYDE of L'Arc~en~Ciel) and in Japanese commercials advertising the popular game Metal Gear Solid 2: Sons of Liberty.
Rumours of a Gackt-based Squall seem to be based on two main things: hair and jacket. In the March of 1998, a CD booklet was released that depicted Gackt wearing a dark-coloured jacket with a fur collar, much like that of Squall's. Also, Gackt's hair is very similar in style to Squall's. In a television program, Gackt has stated that Squall was modelled after him, however Squall's character designer Tetsuya Nomura denys this claim.
More information here.
River Jude [Bottom] Phoenix
Born on August 23, 1970 in Metolius, Oregon, River was an american film actor. Nominated for an Oscar in 1988, he was praised for his acting abilities by his fans and critics alike. Before his death of drug overdose in 1993, he managed to accumulate quite a list of filmography, and now has many musical tributes and references to him from friends and fans all over the world.
Tetsuya Nomura has stated that River was the basis for Squall Leonhart. Squall and River share a similar appearance aswell as a tendancy to frown rather than smile. The also have the same birthday.
Leonhart (レオンハルト)
Leonhart, or Leon as he is more often known, is a character of the supporting cast of Final Fantasy II. He acts as Maria's, one of the three lead character's, brother. Through out the story, he shifts from good to bad to good again, finally helping the main party defeat the evil antagonist of the game.
It is rumoured that he is the namesake for that of Final Fantasy VIII's protaganist: Squall Leonhart. Also, Squall takes the name of Leon during his role in Square-Enix's Kingdom Hearts.
