The Palme d'Or went to Romanian director Cristian Mungiu for the drama "Fjord."
"Cinema remains a way to talk about society, fears and coexistence even during global tension," Mungiu said.
Guests included Sharon Stone, John Travolta, Monica Bellucci, Pedro Almodóvar, Isabelle Huppert, Zoe Saldana, Eva Longoria, Tilda Swinton and Penélope Cruz. Demi Moore was a member of the jury. Critics called the festival one of the strongest in recent years, with a renewed focus on auteur and intimate dramas.