Billie Eilish’s brother, Finneas, marries longtime girlfriend Claudia Sulewski

Finneas O’Connell and his longtime girlfriend, Claudia Sulewski, are officially married.

The brother of Billie Eilish and the actress tied the knot during a star-studded wedding hosted at San Ysidro Ranch in Santa Barbara, California, on Saturday.

According to photos obtained by Deuxmoi, the “Birds of a Feather” songstress officiated the outdoor ceremony.

Among those in attendance were Justin Bieber and his wife Hailey, Dax Shepard, Kristen Bell, Nina Dobrev, Emma Chamberlain, Jason Sudeikis, Carter Gregory, Stassie Karanikolaou and Rachel Sennot.

Eilish’s boyfriend, Nat Wolff, also made an appearance.

Sulewski wore several Oscar de la Renta-designed dresses throughout her wedding weekend.

The “Shrinking” star’s favorite look, however, was her ceremony off-the-shoulder ball gown with a drop-waist bodice.

The classy dress was finished off with a scarf neckpiece.

“We were putting it on, and I was saying, there’s something about this dress that just demands a moment of silence,” she told Vogue in a final dress fitting ahead of the wedding.

Eilish also virtually attended the dress fitting, gushing over her now-sister-in-law during a FaceTime call.

“My God, I can’t believe it,” the Grammy winner said.

“You look like an angel. Sorry to be interrupting. Love you so much.”

O’Connell, 29, and Sulewski, 30, first crossed paths in 2018 on a dating app. Hours after meeting in person, the songwriter had written the track “Claudia” and immediately sent it to her, he told BuzzFeed Celeb in a 2019 interview.

The YouTuber was also the muse behind her now-husband’s 2022 track “Mona Lisa, Mona Lisa” and she also starred in the music video.

O’Connell and Sulewski got engaged in September 2025 during a romantic mountaintop date.

“forever and ever 9.22,” they captioned a joint Instagram post.