Billie Eilish and Finneas O’Connell are siblings, frequent collaborators, and above all, best friends.
On Wednesday, July 30, O'Connell—who performs mononymously as Finneas—celebrated his 28th birthday. To mark the occasion, Eilish shared a special throwback photo from their childhood.
In the picture posted to Eilish’s Instagram, the “Birds of a Feather” singer is seen as a baby, napping beside a young O'Connell, who appears to be protectively watching over her.
“happy birthday @finneas,” Eilish wrote in the caption. “i am so lucky i get to be your sister.”
Over the course of Eilish’s career, O'Connell has co-produced every one of her albums. He’s also produced for artists like Selena Gomez, Tate McRae, Justin Bieber, and Kid Cudi. O'Connell is also an artist in his own right, with two studio albums under his belt—2021’s Optimist and 2024’s For Cryin’ Out Loud.
As they’ve grown as individual artists, they’ve found that they can’t always be by each other’s side when they perform. But in an interview with NPR published last December, Eilish expressed that the two maintain their support for each other from afar.
“It's been different,” she said at the time. “It's very different. It's like we've been talking about it for a really long time, and then when it got closer, it was, like, getting real. And it was suddenly, like, really, really, really, bittersweet and really sad. And then what's amazing is Finneas is, like, really, finally, I feel, like, getting to flap his wings and doing his own show. And he's on his own press tour. And, you know, I'm like, ‘oh, God, Finneas is working so hard now.’”
It looks like 28 will be a big year for Finneas. On September 19, he will drop The Dream, a collaborative album with singer Ashe. Back in June, the two announced that they had formed a supergroup called The Favors.