FINNEAS and Claudia Sulewski are officially married-but Billie Eilish was entrusted with far more than a place in the front row.
The 24-year-old superstar officiated her older brother's wedding, standing before the couple as they exchanged vows during an intimate outdoor ceremony at the luxurious San Ysidro Ranch in Montecito, California. Billie reportedly wore a dramatic dark-green corseted gown for her very important assignment.
The August 29 celebration may have been described as a family affair, but its guest list looked more like an awards-show seating chart. Justin and Hailey Bieber, Kristen Bell and Dax Shepard, Jason Sudeikis, Emma Chamberlain, Nina Dobrev, Rachel Sennott, Rebecca Black, Devon Lee Carlson, Stassie Karanikolaou and Jesse Jo Stark were reportedly among those attending. Billie arrived with Nat Wolff, with the pair remaining close throughout the festivities, according to TMZ.
Finneas and Claudia's dogs, Peaches and Moose, also participated in the celebration as "flower dogs," complete with matching silk bows. Finneas' and Billie's parents, Maggie Baird and Patrick O'Connell, watched as their son married his longtime love.
Claudia Sulewski Turned The Weekend Into A Fashion Marathon
Claudia did not settle for just one wedding dress. The actress, content creator and CYKLAR skincare founder wore four custom Oscar de la Renta creations throughout the weekend.
Her ceremony gown was an ivory silk-faille ball gown featuring a drop-waist bodice, pleated skirt and asymmetrical scarf detail. Her other outfits included a satin rehearsal-dinner dress, a reception look incorporating an upcycled feather peplum and a playful pink after-party outfit inspired by early-2000s fashion. Vogue documented the bride's emotional final fitting.
Despite all the Hollywood glamour, the wedding's most touching detail may have been the family connection at its center. Billie and FINNEAS have spent years making hit records and collecting Grammys together. This time, however, Billie helped her brother begin an entirely different kind of collaboration.
A Love Story That Began With A Dating App-and A Song
FINNEAS, 29, and Claudia, 30, first met through a dating app in 2018. Their connection was apparently so immediate that the musician wrote the song "Claudia" shortly after meeting her.
Claudia later inspired "Mona Lisa, Mona Lisa," FINNEAS' 2022 single. She both starred in and directed its romantic music video, making their personal relationship another source of creative collaboration.
After seven years together, FINNEAS proposed during a mountaintop date in September 2025, presenting Claudia with a cushion-cut diamond ring. The couple announced their engagement with photographs and the simple promise, "Forever and ever."
Now that promise has become official-and when FINNEAS and Claudia needed someone to pronounce them married, Billie Eilish proved that her talents extend well beyond writing, singing and producing hit records.
