The 42-year-old actor has signed on to be part of a star-studded ensemble in the Martin Scorsese-directed film, which is based on former broker Jordan Belfort's best-selling memoir, said The Hollywood Reporter.
McConaughey will play Mark Hanna, the early boss and mentor of DiCaprio's lead character.
The story, which has been adapted for the big screen by Terence Winter, chronicles the dramatic rise and fall of the Wall Street trader and depicts his hard-partying lifestyle and tumultuous personal life, which included battles against drug and alcohol addiction.
The film is scheduled to begin shooting in New York this month.