Finneas and Claudia Sulewski Marry in Montecito Ceremony Officiated by Billie Eilish

Finneas O'Connell and Claudia Sulewski are married. The couple exchanged vows on Saturday, August 29, at San Ysidro Ranch in Montecito, California, according to Vogue. Finneas's sister Billie Eilish officiated the ceremony, as first reported by TMZ and corroborated by Billboard and Harper's Bazaar.

The wedding capped a relationship that began in 2018, when the pair met on a dating app. Finneas, 29, a Grammy-winning producer and frequent collaborator with Eilish, and Sulewski, 30, a YouTuber, actress and founder of CYKLAR Skincare, announced their engagement in September 2025 with a joint Instagram post captioned "forever and ever 9.22." For the wedding weekend, Sulewski wore four custom Oscar de la Renta looks, including gowns for the rehearsal dinner, ceremony, reception and after-party, according to Vogue.

Her ceremony dress was an ivory silk faille ballgown with a drop-waist bodice, pleated skirt and a draped neck scarf that flowed into the train, E! News reported. The guest list included Justin and Hailey Bieber, Kristen Bell, Dax Shepard, Rachel Sennott, Emma Chamberlain, Rebecca Black, Jason Sudeikis, Devon Lee Carlson, Stassie Karanikolaou and Jesse Jo Stark, according to Billboard. Eilish attended with her boyfriend, Nat Wolff.

The couple's parents, Maggie Baird and Patrick O'Connell, were also present, Billboard reported. He told BuzzFeed in 2019 that he wrote his song "Claudia" the day he met her and sent it to her that night. "I wrote the song Claudia about Claudia the day that I met Claudia, and I sent it to her the night that I met Claudia," he said.

"I sent her the first part and she texted me back, 'You're trouble.'" The couple also collaborated on his 2022 solo song "Mona Lisa, Mona Lisa," whose music video Sulewski starred in and directed. In an interview with Harper's Bazaar, she said, "I've been so busy planning a wedding and its surrounding events this year that I've really been off my reading game, which I hate to admit, but it's true!"

She also discussed her interest in pregnancy and fertility topics, saying she was "fully diving into the research" even though that chapter of her life was still far off. Neither Finneas nor Sulewski has shared personal details about the wedding on their own social media accounts as of Sunday. Sulewski has spoken recently about the demands of wedding planning.