Cara Delevingne may have just thrown the party of the summer … celebrating her birthday in L.A. with a guest list full of A-list stars.

It all went down Tuesday night at Chateau Marmont, where some of Hollywood’s biggest names were seen arriving left and right … including Selena Gomez, Paris Hilton, Coleman Domingo, Tiffany Haddish, Raven Symone, Bebe Rexha and more.

Margot Robbie and Jay Hernandez strutted into the party arm-in-arm … and were later swarmed by paps as they left together and hopped into a Waymo.

The birthday girl herself looked all business as she was spotted behind the wheel, pulling up to her own bash with a bouquet of flowers in the back seat.

Things may have been a little awkward for Kaia Gerber and Jacob Elordi … as the former couple showed up separately.

Best dressed? Chrishell Stause and G Flip, no question — the couple was rocking baggy black suits and glossy loafers.