Happy Birthday, Billie! Billie Eilish celebrated her 21st birthday in an epic Christmas-themed bash on Saturday, December 17, just a day before her birthday! The Grammy-winning singer was dressed as Mrs. Claus in a sexy Santa suit and had a three-tier cake decked out with peppermint candies and dazzling disco balls lining the ceiling.

The decor wasn’t the only epic part about the event, as nearly every celebrity in Hollywood was there. No, seriously — from Justin and Hailey Bieber, Kendall Jenner, Avril Lavigne, Dove Cameron and Doja Cat, keep reading for a list of all the stars who celebrated Billie’s big birthday bash!

One of the celeb guests who posted a number of pics from the party was Lil Nas X, who posed with other friends and celebs at the event. The “Montero” singer snapped selfies with Dove Cameron, Lauren Jauregui, and Eric André, among others.

The “bad guy” singer’s party came just one day after Billie performed at a sold-out show in Inglewood, California, where her boyfriend Jesse Rutherford surprised her with a birthday cake on stage to celebrate the special occasion. Jesse was also at Billie’s party, wearing a matching Santa suit, while also dancing and kissing his girlfriend throughout the night.

The songstress first stirred up romance rumors with The Neighbourhood’s lead singer after they were spotted lip-locking on October 18, 2022, a few days before being spotted holding hands by a fan at Horror Nights in Los Angeles. The couple went Instagram official after Billie posted a photo of the two dressed for Halloween.

In her sixth annual interview with Vanity Fair, Eilish answered the question, “Do you have a boyfriend now?”

“Yeah I do,” she said, smiling. “I’m really happy about it. I managed to get my way to a point in my life where I not only was known by a person that I thought was the hottest f–king f–ker alive, but pulled his ass.”

She concluded with, “Jesse Rutherford, everyone!…I locked that motherf–ker down.”

Scroll through our gallery to see all of the stars who attended Billie’s star-studded 21st birthday.

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