STORY: Hadid sported a long black strapless gown with her hair tied back in a plaited bun and Delevingne also opted for black, wearing a dramatic floor-length dress with a train and cut-out diamonds.
Seventy-four-year-old Musk, mother of billionaire entrepreneur Elon, opted for a pleated silver number accompanied by a green beaded necklace.
Hollywood star Jake Gyllenhaal was among the joyful revellers, walking the red carpet with girlfriend Jeanne Cadieu who wore a fun, pink dress with a lips-shaped bustier.
Also in pink was model Jourdan Dunn, who wore patent buckled heels with a pale pink elaborate dress.
The film festival held a special red carpet to celebrate its 75th anniversary, bringing together filmmakers and actors from around the world, ahead of a screening of Louis Garrel's "The Innocent".