Blanchett follows Pedro Almodovar, who headed the jury for the 70th edition of the festival.
"I am humbled by the privilege and responsibility of presiding over this year's jury," Blanchette said in a statement.
"This festival plays a pivotal role in bringing the world together to celebrate story; that strange and vital endeavour that all peoples share, understand and crave."
Pierre Lescure, Festival de Cannes President and Thierry Frmaux, General Delegate, said Blanchett was a "rare and unique artist" whose talent has enriched both screen and stage.
"I have been to Cannes in many guises over the years; as an actress, producer, in the marketplace, the Gala-sphere and in Competition but never solely for the sheer pleasure of watching the cornucopia of films this great festival harbours."
Blanchett won the 2014 Oscar for best actress for her performance in Woody Allen's "Blue Jasmine". She had already won the best supporting actress for Martin Scorsese's "The Aviator".