The English actor, 36, was first reported to be in talks for the film in June, after he last starred alongside DiCaprio in 2010’s Inception.
Alejandro Gonzalez Inarritu is signed on to direct, with shooting scheduled to begin on 22 September.
The storyline is based on Michael Punke’s novel, The Revenant: A Novel of Revenge, and set in the 1820s.
It follows the life of fur trapper Hugh Glass, played by DiCaprio, who is left for dead and robbed by his comrades after a bear attack. He survives against the odds and swears vengeance for their betrayal.
DiCaprio's character is described as "deserted, defenceless and furious".
The film, adapted from the book by Inarritu and Mark L Smith, is set for an autumn 2015 release date with more details yet to be announced.
Will Poulter fromWe’re the Millers, has been mentioned as a possible cast addition.
The 21-year-old will next be seen in The Maze Runner in September and has also finished filming Glassland with Toni Collette.
Hardy, meanwhile, is known for his role as Bane in The Dark Knight Rises. He next hits silver screens in The Drop, also due out this September, before starring as both Kray twins in Legend.Reuse content