After a runway event so major it finished with a live Backstreet Boys performance, we didn't think life could get any better for designer Olivier Rousteing. But on the heels of last week's Balmain x H&M catwalk [1], Rousteing was feted by his own #Balmainarmy of models and half of Hollywood's best dressed for an epic 30th birthday party. Appearances from Justin Timberlake [2], Jessica Biel [3], Kate Hudson [4], and, of course, the Kardashian-Jenners, all in Balmain, made this a fashion gathering so huge, we don't think we've seen a guest list like it since Fashion Week. Scroll on to get a VIP look at one of the biggest — and best-looking — parties we've ever seen.
Jaime King partied the night away in a ruffled, one-shoulder mini.
Kendall Jenner got her "smize" on in a peplum-trimmed top and skirt.
The birthday boy hugged it out with a stripe-happy Jada Pinkett Smith [5].
Kylie Jenner and Tyga coordinated in all white.
Jennifer Lopez [6] heated up the party in a devastatingly sexy cutout look.
Jessica Biel [7] made an appearance in a ruffly mini alongside Olivier.
Kylie took a time out to pose for the camera.
The Balmain army in all its glory.
Alessandra Ambrosio celebrated with Olivier.
Rachel Zoe [8] suited up in a bold multicolor look.
Kourtney Kardashian kept things understated.
It wouldn't be a Balmain party without an appearance from Kim Kardashian [9], who selected a see-through top and pencil skirt.
The supermodel crew showed off their stems.
Kate Hudson [10] shimmered in a gilded minidress.
Justin Timberlake [11] joined his wife and the guest of honor.
Hannah Bronfman and Brendan Fallis brought their chic style game to the party.
Kris Jenner was ready to party in a Balmain blazer, alongside Jennifer Rade, Mary J. Blige, and Jada Pinkett Smith [12].