Andrew Greene is suing the makers of the Leonardo DiCaprio film for $25m (€18m) and claims the movie has "permanently damaged" his reputation.
The Paramount Pictures movie, which is nominated for five Oscars, is based on the 2007 memoir by Jordan Belfort, a hedonistic broker whose activities made him a millionaire but soon attracted the attention of the police.
Greene was a friend of Belfort's and was employed as the head of corporate finance at his firm in the 1990s.
The character Nicky 'Rugrat' Koskoff is thought to be based on him and the hairpiece he wears in real life.
In the film, directed by Martin Scorsese, Koskoff is shown shaving the hair off a woman who is then given $10,000 (€7,300).
"Mr Greene's character is shown doing cocaine on company premises during business hours in another scene," the suit said.
"The motion picture included other scenes depicting Mr Greene's character in a reckless and depraved manner, including more than one scene wherein his character is depicted having sexual relations with a prostitute."
The complaint added: "Mr Greene will be permanently linked to the crimes and loathsome behaviour portrayed by his likeness in the motion picture, despite never having been interviewed, questioned, charged, imprisoned, or even arrested for the illicit and despicable behaviour shown in the motion picture."