Olivier Rousteing's Epic 30th Birthday Puts All Other Parties to Shame

Updated on Oct 26, 2015 at 10:15 AM

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, 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, Jessica Biel, Kate Hudson, 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.

Kylie Jenner and Tyga coordinated in all white.

Jennifer Lopez heated up the party in a devastatingly sexy cutout look.

Jessica Biel 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 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, who selected a see-through top and pencil skirt.

The supermodel crew showed off their stems.

Kate Hudson shimmered in a gilded minidress.

Justin Timberlake 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.