All About Billie Eilish's Brother Finneas and Their Sibling Bond

Billie Eilish has said that her brother Finneas O'Connell is her "best friend forever."

In a sweet Instagram tribute for his 26th birthday, Billie wrote that she "will never love anyone as much as" she loves her older sibling, adding, "You are the best thing I have."

Finneas has been by Billie's side personally and professionally throughout her entire life and supported her through her rise to superstardom, serving as Billie's co-writer and producer for all of her award-winning projects. Finneas told The Washington Post in 2020 that he wouldn't have it any other way, even though it means his solo career typically takes a backseat to collaborating with his sister.

"In the alternate reality where I wasn't involved at all, and I'd been like, just, sweating my way through, trying to have a music career for years? And then my sibling had one and I wasn't involved at all? I think I'd be very tortured by it," he said. "But the fact that we've had one in tandem makes a lot of sense."

The career they've had together has been massively successful, including nine Grammy wins, two Golden Globes for best original song ("What Was I Made For?" and "No Time to Die") and a Best Original Song Oscar for the latter. In 2024, Billie and Finneas won their second Oscar for the song “What Was I Made For?” from Barbie.

From their childhood to their record-breaking musical collaborations, here is everything to know about Billie Eilish's bond with her brother, Finneas O'Connell.

His parents recognized his musical talent early on

Finneas was born in Los Angeles on July 30, 1997. He and Billie, who is four years his junior, were raised by their two parents, each of whom worked in entertainment: their mother Maggie Baird is an actor, screenwriter and musician and their father Patrick O'Connell is an actor and musician.

Baird and O'Connell homeschooled Billie and Finneas and helped cultivate their innate songwriting talent. Finneas began writing and composing music as a child and played several instruments from a young age.

"Patrick and I would hear something, and walk into the room and go, 'Who wrote that?' " Baird told The Washington Post. "And he'd go, 'I wrote that.' Every time. I remember telling a person or two who was a singer or a songwriter, I'd be like, 'I don't know what to do, my son has this crazy talent.' "

Finneas joined his mother's songwriting class when he was 12 years old and confirmed her suspicions: he was great at making music.

"It's as if she handed him a songwriting Rubik's Cube, and he solved it in three seconds," O'Connell said. Still, the father-of-two insisted that he and Baird didn't push Finneas to pursue music professionally. "We have never put any kind of emphasis on getting a job and making a living. If we modeled anything, it was being broke and artsy," O'Connell said.

He was an actor before focusing on music

Before he was known as an acclaimed producer, songwriter and singer, Finneas was a working actor — and his biggest roles played to his musical talents.

As a child, he played Spencer, a student in the 2011 Cameron Diaz comedy Bad Teacher. When he was a teenager, Finneas guest-starred on seasons 4 and 6 of Modern Family. The producer also acted as Alistair on Glee season 6. He previously told The Washington Post that appearing on the show as it was winding down was a bit of a strange experience.

"I definitely felt like I'm part of the end of this seminal thing," Finneas said. "It's so funny to be doing your fourth episode of a show and everybody's weeping, and it's like, their 130th episode."

Finneas has also starred in independent films, including Life Inside Out (which was written by and costarred his mom) and Confessions of a Teenage Jesus Jerk.

In 2022, Finneas had a voiceover role in which he got to flex his pop star muscles: he wrote music for and played Jesse, a member of the fictional boy band 4*Town, in Disney/Pixar's 2022 animated film Turning Red.

He originally wrote "Ocean Eyes" for his band

Finneas was a member of a rock band called the Slightlys as a teen. After winning a contest and performing at the Vans Warped Tour when he was 15, he actually questioned whether he wanted to keep making music.

"Even that one day was so heatstroke-y, and so hectic and stressful that I was like, 'This thing I thought was my lifelong dream is not my dream at all,' " he recalled to The Washington Post. Still, Finneas kept at it, and when he was 18, he wrote "Ocean Eyes" for the band, describing it as "a big, soaring electric guitar and drum record."

It didn't work for the Slightlys, but it did work for his younger sister. Finneas and Billie worked to deconstruct and re-work the track together, releasing it on SoundCloud in 2015 and then watched it blow up.

"The best part about it was it was such baby steps, comparatively," he said. "The first night was a thousand streams, and we were like, 'Oh my God!' Then a week later, it was 10,000, two weeks later it was 100,000. They weren't Bieber YouTube numbers, where you'd put up a Justin Timberlake cover and you’d get 15 million. We appreciated every step of the way."

Billie prefers working with him

Billie and Finneas work well together in part because she is not a fan of the typical recording experience, especially with other co-writers.

"She doesn't like going to some big studio and having them pretend to be a therapist for a couple hours," he explained to The Washington Post. "So by default, we always make the good stuff together."

Finneas told Rolling Stone in 2022 that he works with Billie so she will get what she wants out of her sound and affirmed that she has the final say on everything they create together.

"I always really firmly had this sort of, 'Let's have this be your name. You're the star of the videos. The songs are about your life, and then I'll do [my thing] separately,' " Finneas said. "I'm not afraid to speak my mind, but I also have a feeling of when she's like, 'I hear what you're saying, but I prefer the other way.' "

While making their album Hit Me Hard and Soft, Finneas and Billie got into one of their "longest, biggest" arguments to date.

"[It] was during a period of transition in maybe both of our lives where we were both just trying to be honest. To give you credit, I was very much like high and mighty about like, 'You're not being honest enough or authentic enough,' " the music producer said during an appearance on Hot Ones Versus with his sister in July 2024.

Finneas continued: “And you were coming up with such beautiful melodies and cool cadences. Then, by the time we had cool lyrics, everything else was done. So I learned a lot from being too ego-centric.”

He made Grammy history

Finneas has 10 Grammys and 17 nominations to his name. In 2020, he set the record for the youngest person to ever win the Grammy for producer of the year, non-classical, at age 22, for his work with Billie on When We All Fall Asleep, Where Do We Go?.

In 2022, Finneas was nominated for best new artist for his solo work, as well as for song of the year and record of the year for Billie's "Happier Than Ever," and album of the year for Justin Bieber's Justice and Happier Than Ever.

"It's a huge honor," Finneas said of being recognized for his solo work during the Live from E!: Grammys special. "I love making music and any recognition for something you love doing is just validation that you get to keep doing it."

His girlfriend is an actor and YouTuber

Finneas has been dating YouTube star and Instagram influencer Claudia Sulewski since the pair met on a dating app in 2018. He wrote the song "Claudia" about her on the same day that they met. A year later, Finneas told BuzzFeed that he sent her the first part of the song the same night they met and she replied, "You're trouble," which he then worked into the rest of the lyrics.

It wasn't the only time they'd work together: Sulewski also directed and starred in Finneas' music video for "Mona Lisa, Mona Lisa" in July 2022. The video features footage of the couple together in Paris, as well as frolicking on the beach with their dog Peach.

Sulewski has acted in some short films and series and worked alongside Patton Oswalt in the movie I Love My Dad in August 2022.

He works with many artists

Finneas has written and produced for a slew of top pop acts besides Billie, including Selena Gomez, Halsey, Camila Cabello, Ben Platt, Girl In Red, Tove Lo and Julia Michaels — just to name a few. He told The Washington Post he realizes his songwriting and producing credits are largely for female artists, and said that there's a reason for that.

"It's definitely femme heavy on my résumé. I think there's a real vulnerability to the lyrics I'm interested in writing," he said. "And I think there are a lot of incredible women in music right now that are willing to be vulnerable, and there's a little less male vulnerability."

Tove Lo told The New York Times in 2021 that Finneas is "really good at finding the 'nerve' " of a song, explaining that he's "not so focused on the format, but what feeling you want to feel next in the song."

He doesn't want to be as famous as Billie

Finneas has said that watching Billie adjust to fame made him realize that he doesn't want to achieve that level of celebrity.

"Billie gets to play these arenas and whatever, but her day-to-day life is more challenging than mine," he said on the Song Stories podcast in 2022. "My ability to walk down the street and go into a grocery store and sit at a coffee shop and whatever is uninhibited. Maybe a kid or two that day comes up to me and goes, 'Hey, I love you,' or something, but it's not a challenge."

Despite wanting to be able to enjoy everyday life without fame, Finneas says that if it's a choice between making music that gets him recognized or ditching his dream, he'll take the spotlight.

"I'm proud of my music. I want to promote it. I want it to be heard by as many people as possible. And if the consequence of that is that I become more famous, I'm willing to take that," he said. "I think a lot of people want to be famous, but I have no desire to be any more famous than I currently am. It seems like a huge drag."

He and Billie wrote a song about their bond

In November 2019, Billie released the track "everything i wanted," a tribute to Finneas and their closeness. She said in a statement at the time, "This song is one my brother and I wrote about each other. No matter what happens, we always have been and will be there to make it better." In the lyrics, Billie sings, "If I could change the way that you see yourself / You wouldn't wonder why you hear / 'They don't deserve you.' "

The sibling pair later revealed to The New York Times that the song started as a piece Billie wrote about going through a severe bout of depression, and it took them more than a year to finish it.

"It was a period where I was really worried about my sister, and I felt like an enabler in helping her write a song as bleak as that song was," Finneas explained. "A lot of songs are written in retrospect, but this one felt like it was being written in real time, and I was like: 'This is something we’ve got to write on the other side of this hill. We have to go through this in real life. You can't always solve your problems in a song.' "

Billie convinced Finneas and their mother to let her record the song when she explained to them that creating art from her pain was a way to heal. "We had a complete block," Billie recalled. "And the way we got through it was to make it about us as siblings and what we mean to each other."