Kardashians Party Alongside Smiths, Justin Timberlake and JLo at Balmain Birthday Bash -- See the Pics!

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The Balmain Army came together Friday night to celebrate a VIP 30th birthday.
The Kardashian-Jenner crew -- including Kim, Kourtney, Kris, Kendall and Kylie -- and the Smith family (minus Will), were among the big names celebrating Balmain creative director Olivier Rousteing's birthday.
Photo: Stefanie Keenan/Getty Images for Apple
A-listers like Jennifer Lopez, Kate Hudson, and Cara Delevingne, as well as Justin Timberlake and wife Jessica Biel, were just a few of the partygoers celebrating at a private residence in Los Angeles' Hollywood Hills on Friday.
Photo: Stefanie Keenan/Getty Images for Apple
Longtime, outspoken Balmain fan Kim shared plenty of photos from inside the soiree. The pregnant reality star's "squad" for the night included her mom and sisters, Jada Pinkett-Smith and her kids, Willow and Jaden, and Mary J. Blige.

While all of the Keeping Up With the Kardashians stars wore Balmain, it was the youngest who stole the show in a curve-hugging cut-out knit dress.
"I love you @olivier_rousteing thank you for this beautiful dress," Kylie captioned an Instagram post, showing her cuddled up to the birthday boy.
Whiel Khloe Kardashian was noticeably absent from the festivities, as she continues to stand beside Lamar Odom during his recovery, Kylie's boyfriend, Tyga, helped everyone celebrate by rapping for the fashion mogul.
The Kardashians weren't the only ones enjoying themselves at the fête. Justin and Jessica have been making more public appearances lately after taking a hiatus from the spotlight following the birth of their 6-month-old son, Silas, and the new parents looked radiant as they helped Olivier belatedly ring in the big 3-0.
JLo looked equally as glowing as she stood by boyfriend Casper Smart's side during the shindig.
Photo: Stefanie Keenan/Getty Images for Apple
Check out even more fun pictures from the party below.

It has been a big week for Rousteing, who also debuted his line for H&M Balmain. The collaboration hits select stores Nov. 5.
He also wasn't the only one who had a massive party recently -- Kanye West threw Kim a surprise bash for her 35th birthday earlier this week. See pics from her fun party in the video below.