Billie Eilish's Latest Hairdo Has Fans Realizing That She Actually Looks Like Her Brother Finneas

Billie Eilish is back on Instagram, and she brought a whole new hair era with her. It all went down on October 5, when Eilish surprised fans with a new reveal—and kept her message about it hilariously short: “hi.”

True fans, however, know Eilish loves a good hair transformation. From icy silver and electric blue to deep reds and dark brunette, the singer has rarely met a shade she couldn’t turn into an era.

Some of her most memorable looks have become almost inseparable from the music that came with them. Her black hair with neon green roots became a signature during her early rise to fame, while 2021 brought one of her biggest switch-ups yet when she traded the two-tone look for platinum ahead of Happier Than Ever.

Check out her blonde bombshell transformation below:

For Eilish, those colors have become more than a revolving door of shades. She has spoken about how closely certain looks became tied to her sense of identity, extending beyond her hair and into her fashion and overall aesthetic.

Eilish reflected on the hair eras that felt the most personal to her:

“Well, I really like to romanticize two specific periods in my life: the green roots and the red roots. Green and black especially felt like such a personal and career-defining look for me. I felt so exactly who I was at that time.”

Eilish eventually left the platinum behind, returning to brunette before warming things up with auburn and copper tones more recently. After nearly two months away from social media, she apparently decided that chapter had run its course, resurfacing with a shorter, much lighter shade.

See the post that got fans talking:

Okay, Billie. We see you. From the strawberry-blonde shade to the choppy, shoulder-skimming layers and dramatic side part, the whole thing is giving cozy fall makeover with just enough edge to remind us who we’re dealing with.

Call it "Birds of a Feather," because the whole look came together... But it’s not like you’ve never seen this look before:

Turns out, the familiar face was hiding in plain sight. Eilish now bears an even more striking resemblance to her older brother, Finneas O’Connell, the singer-songwriter and producer she has collaborated with throughout her career.

And apparently, we weren’t the only ones making the connection. Some commenters admitted the new hair was what finally made the sibling similarities click, while others seemed genuinely stunned they hadn’t noticed it sooner. Once Finneas entered the conversation, though, there was really no going back.

See how the internet reacted:

@finneas.f/Instagram

@yelyahwilliams/Instagram

@billiieelilsh/Instagram

@amazonmusic/Instagram

@avadinii/Instagram

@eilish9034/Instagram

@extremecandyfloss/Instagram

@angelzarat24/Instagram

@elliotleeofficial/Instagram

@wherearetheavocados251/Instagram

@lyckelo67/Instagram

@ira198973/Instagram

Hair aside, Eilish has another transformation coming—this time on the big screen. She recently wrapped filming on Sarah Polley’s adaptation of Sylvia Plath’s The Bell Jar, where she stars as Esther Greenwood in her feature-film acting debut.

Based on Plath’s semi-autobiographical 1963 novel, the story follows Esther, a young woman whose mental health begins to unravel while she spends the summer working at a magazine in 1950s New York City. The story explores her struggle with severe depression, identity, and societal expectations.

It’s a weighty role for a first feature film, but rumored beau Nat Wolff doesn’t seem to doubt Eilish’s ability to take on just about anything. The actor and musician, who has been romantically linked to Eilish since 2025, previously praised her seemingly endless list of talents.

Wolff made his confidence in Eilish pretty clear:

“She’s one of those people where almost everything she does, she does better than everyone else.”

Wolff would know a thing or two about working alongside her. He starred in Eilish’s self-directed music video for "Chihiro," while he and his brother, Alex Wolff, also opened for her on tour. Eilish has previously referred to the brothers as her “best friends in the world.”

Whether that friendship has officially turned romantic remains something Eilish and Wolff have kept to themselves. But with a fresh look, her feature-film debut, and fans already hunting for clues about what she might be planning musically, Eilish is keeping everyone guessing.