JoJo Siwa was not the most popular person at her 16th birthday because she had superstar spawns North West and Penelope Disick there to help ring in her monumental day!

The YouTube star held her big party on Tuesday night at The W Hotel in Hollywood. The event will be part of a Nickelodeon special entitled, "JoJo’s Dream Birthday," set to air on Saturday, May 18, at 8:00 PM. JoJo doesn't actually turn 16 until next month.

Wearing her signature giant bow and nothing but neons and sparkles, North and her BFF Ryan looked ecstatic to stand next to JoJo.

The two go way back, as in last week. North is a well-documented fan of JoJo and they were seen filming an upcoming special together for the former dancer's YouTube channel.

https://www.instagram.com/p/BvooQP6Hh8m/

While North was the spitting image of her idol, Penelope showed her own style wearing a rainbow sequined sweatsuit with her adorable bob.

But the famous "KUWTK" cousins weren't the only famous guests at JoJo's sweet 16.

Her former dance teacher, Abby Lee Miller, and "Fuller House" star Jodie Sweetin were there to celebrate with the teen too.

Penelope Disick

North West & Penelope Disick Ring in JoJo Siwa's 16th Birthday With a Whole Lotta Sparkles