MILLY ALCOCK

She rode dragons in Westeros and scammed Julianne Moore on Sirens. SAVANNAH WALSH talks to Hollywood's real live Supergirl

SAVANNAH WALSH

VANITIES

"My mother instilled this blind confidence within me: 'If those idiots can do it, why can t you?' Her words, not mine." Alcock laughs. "It just lit a fire under my arse."

Milly Alcock's mind was working overtime. "I kept getting these crazy dreams—this image of me at the foot of a tsunami," she says from the safety of her couch in London. It must have been the tidal wave that comes with starring as a canonical superhero. "Of course I'm scared," she says. "Of course I want people to like me and the movie. But ultimately, it's out of my control."

She's surrendered to adoration before. In 2021 Alcock left her native Australia to film the Game of Thrones prequel series House of the Dragon in Britain. Then Alcock landed Sirens, Netflix's sardonic limited series. Now, scared or not, Alcock is poised for her biggest break yet, in Warner Bros.' Supergirl in theaters this June.

Raised in Petersham, a middle-class suburb in west Sydney, by a single mother who worked as a nanny, Alcock idolized some of Australia's most successful exports: Cate Blanchett, Rose Byrne, Sarah Snook, Heath Ledger. But breaking into show business with no familial connections meant she had to hustle. At the age of 13, Alcock began cold-calling talent agencies. "We struggled financially, so it really pushed me to be assertive," she says. "My mother instilled this blind confidence within me: 'If those idiots can do it, why can't you?' Her words, not mine." Alcock laughs. "It just lit a fire under my arse."

During her senior year of high school, Alcock nabbed a role in the Australian series Upright. Was quitting school for TV a tough sell for Alcock's mother? "She told me to do it," says Alcock. Her mother is dyslexic; Alcock, too, struggled academically. "Iwas bad at school—that was branded as naughty. We have this weird halo effect that if you're a clever kid academically, then therefore, you are good. Acting was the only thing that I was given that halo for, and it's intoxicating to be chosen like that."

After a cameo appearance in last year's Superman, Alcock gets top billing as Kara Zor-El/Supergirl. "She's given this incredible responsibility and doesn't know how to deal with it," says Alcock. "So she kind of suffocates herself and goes on a journey of self-discovery." It was only when production ended—and her tsunami nightmares abated—that Alcock realized: "That's me, man. I'm the mess." Or rather, she used to be: "I'm not the mess anymore."

In comic book lore, Kara lives through the destruction of her home planet before arriving on Earth. "She's not trying to save the world—she's just trying to save her own," says Alcock. "This film is an excellent reminder that the world can be crumbling around you, but you can be the hero of your own story."

Alcock has long strived to keep her eyes on her own paper. She didn't probe her costar Julianne Moore for advice between takes on Sirens: "You have to respect that they don't owe you that," Alcock says. She also didn't look for guidance from any previous onscreen Supergirls, including actors Melissa Benoist and Sasha Calle. "They're just people living their lives," Alcock says, a shrug evident in her voice. "It's not like we have this blood bond."

After House of the Dragon, Alcock also swore she'd never do another big franchise project. But when she didn'twork for a year after the conclusion of Sirens, professional anxiety began to creep in. "I was so shitscared that my life was over at 22," she says. "And, of course, itwasn't." When the opportunity to play the Girl of Steel came along, she says, "I kind of bullied myself into it."

Has the famously fickle Game of Thrones fandom prepared Alcock for the inevitable backlash she'll face? "It definitely made me aware that simply existing as a woman in that space is something that people comment on. We have become very comfortable having this weird ownership of women's bodies," she says. "I can't really stop them. I can only be myself."

Filmmakers like Martin Scorsese and Ridley Scott have also shared theirown misgivings about the superhero genre. Alcock doesn't mind: "I get it. They've been around for fucking ever making phenomenal films," she sayswhen asked a question she'll inevitably face during the looming Supergirl press tour. "Not every film is for everyone. The beauty of art is that you can be selective."

For her next moves, Alcock has selected Thumb—a comedy about a severed digit featuring Sofia Vergara and Kate McKinnon—and Hot Mother, about a mother (Toni Collette) and daughter (Alcock) who get trapped in a sauna at a remote wellness spa. After that, "I want to work with a bunch of really cool young women," Alcock says. "Rachel Sennott is fucking fab. She's pioneering the Gen Z voice at the moment. I'm excited to see how this generation reflects our insidious day-to-day relationship with the internet and parasocial relationships."

Alcock's own Instagram, where she posts for an audience of nearly 2 million followers and counting, is charmingly uncurated. She hard-launched her relationship with London-based chef Joseph "Jo" Powell in June 2025 by sharing an image of Powell wearing an "I Love My Girlfriend" shirt. "I don't really think about it, which is bad," she says, petting her new kitten—a black Persian who bears a strong resemblance to the bug-eyed soot sprites in Hayao Miyazaki's Spirited Away. "Everything that happened to me careerwise didn't make me rethink who I am. I'm sure bad thingswill happen, and I'll have to be more conscious. But at the moment I'm just a 25-year-old girl living in London. I'm not trying to brand myself."

FOR DETAILS, GO TO VF.COM/CREDITS.