It’s bright and early in New York City, and it’s the morning after for Milly Alcock.

Yesterday evening, the actress, 26, hit the red carpet for the huge East Coast premiere of her new movie, Supergirl, in which she stars as the titular DC heroine. It was the culmination of a whirlwind few months that have seen her take part in a breathless global press tour, attend glitzy events in LA and London, and appear on some of the biggest talk shows in the world. Tonight, she will grace Jimmy Fallon. “Most of the time, it just kind of feels like this is all happening to somebody else,” she says of a life currently lived at lightspeed.

DC bosses were touting Alcock as the next Supergirl long before she auditioned for the role in 2024. At the time, she was in the Game of Thrones spin-off, House of the Dragon, as the young Rhaenyra Targaryen when James Gunn, co-chairman and CEO of DC Studios, spotted her and suggested to co-CEO, Peter Safran, that she could be their new Supergirl. Alcock was with her family in Sydney, Australia when the call came through asking her to make a tape. “A week later, I was on a plane to Atlanta doing my first-ever screen test,” Alcock recalls. 

Ten days later, Gunn sent her a message. “He just sent me a link to a Deadline article saying that I’d gotten the part,” she laughs. “The article was literally the first time I heard: I was like, ‘You could’ve called me, man!’ This is news for a phone call!” 

Alcock has come a long way since being a determined kid from a small Sydney suburb who dreamed of being an actor. At school, drama was her escape: she struggled in other classes despite working non-stop and was even held back a year while she caught up. Alcock received an ADHD diagnosis recently and says it helped her to reframe this time. “It made me look back on my younger years with a lot more empathy because I was just someone who really, really, struggled [in] school,” she explains of her neurodivergence. “No matter how hard I tried, I just couldn’t quite get my grades up. It was really validating to have something be the touchstone for why that was.” 

Her breakthrough role came via Upright, an Australian comedy series she starred in as street-smart runaway teen Meg Adams alongside Tim Minchin. She says the role “changed her life,” and singles out Minchin for being the one to set her on her way. “He was the first person to ever really see me,” she explains. “I truly believe that each and every one of us just needs one person to see us and then we’re unstoppable.” She still looks back on this time as her most formative. “It was the start of everything for me. I’m still incredibly proud of this role.”

Alcock’s iteration of Supergirl, aka Kara Zor-El is based on Tom King and Bilquis Evely’s comic miniseries, Supergirl: Woman of Tomorrow. Alcock’s portrayal is one of the most relatable—and human. Unlike her cousin, Superman/Clark Kent, Kara isn’t clean cut. She is frequently hungover and looks dishevelled, with wild, unkempt hair. She’s punky and anarchistic, wears a Blondie t-shirt and likes to get lost in her headphones to a soundtrack of Wolf Alice and Wet Leg (this was Alcock’s own idea, being a fan of both). She also loves a good barb, is quick witted and fun—and very, very cool. 

At a time when cinema is still suffering superhero fatigue after a decade-long expansion of the genre, Alcock thinks that Supergirl brings something different to the table on account of how relatable her character is. “A lot of times in films within this genre, the audience is told who to be,” she says. “This film is a beautiful exception where they’re shown who they are. I think that a lot of young people will really resonate with her messiness and her flaws. I was really excited to play someone so surprising.”

One of the most emotive moments for Alcock came when she wore the Supergirl outfit for the first time as she prepared for a cameo in last year’s Superman alongside David Corenswet. Parts of her outfit were made from some of Christopher Reeve’s original, iconic Superman costume. “I remember wearing the costume as we went to do a take and our [executive] producer, Chantal [Nong Vo], started crying,” Alcock recalls. “She was like, ‘I’ve been trying to make this film for five years—it’s incredible to see you here.’” At this point, the full weight of becoming Supergirl suddenly hit Alcock. “That was when I really understood the responsibility of the role, not only for the fans, but for the people who are making this film.” 

One of the hardest things, Alcock says, was her family being so far away in Australia during this time. She grew up with her mother and two younger brothers in Sydney before moving to London. “It’s so difficult to be going through such a momentous change and for them to be on the other side of the world,” she reflects. Day one on set, she says, was “incredibly overwhelming,” but praises director Craig Gillespie for creating an on-set environment that didn’t feel like a blockbuster, but one that felt like they “were creating an indie film.” She continues: “There was such an intimacy and such collaboration with everyone involved. It was so fulfilling.” 

Once her nerves had settled, Alcock enjoyed getting into the swing of things. She trained every day for four months with a PT before working with stunt teams on carefully choreographed action sequences. She also valued some advice Corenswet gave her. “It felt like I had a friend within the world who kind of understood what I was going through,” she reveals. “He also just told me, ‘You’re going to get a lot of bruising, and you’ll be very proud of the bruising,’ and he was correct,” she asserts, saying all the gruelling training and stunt scenes were worth it. “It’s been an incredibly life changing experience. I’ve learnt so much about myself, about the world I’m stepping into and am a part of, and it’s been such a privilege to watch all of the fans become so excited. They’re so dedicated and loyal. I’m really excited for it to be out in the world and for them to finally get to meet our Kara.”

One of the things she seems particularly proud of are the film’s feminist undertones. Alongside Alcock, rising British star Eve Ridley (Ruthye) is front and centre with her, and one of the film’s central storylines surrounds the patriarchal treatment of a group of women. Alcock says it’s all down to the film’s writer, Ana Nogueira.

“I think that Ana has had the wonderful, but sometimes absolutely painful, gift of having once been a young woman, a teenage girl. I think that the heart of the story really lives and dies in these two young women, Kara and Ruthye, and their ability to hold each other up. They both kind of help resolve their own grief through one another. 

“I also love how the film isn’t cantered around love or male validation,” she continues of the plot. “I really hope that it reflects what a modern-day hero can be for young women—and for young boys too. I want little boys or young men to go see this film and be like, ‘I want to be as strong as her. My sister is as cool as her.’ I want them to be able to see parts of themselves within the character, but also to see the strength within the women around them.” 

Alcock is aware that there is a long way to go, particularly when it comes to online responses to women leading major franchises like this.She says she’s become adept at switching off from the comments. “I think what [House of the Dragon] taught me is that people are going to have their opinion about what you’re doing or whatever you’re a part of, and they’re going to let you know about it. But ultimately, you have to shut it out, shut out the noise, because you can’t really change their minds.” 

She continues: “I don’t have the power to change the world or public opinion. And I think choosing what realm to engage in and to exist in is incredibly important for the mental health of anybody who’s publicly facing. I think that we’ve entered a new arena where sometimes people validate the online world more than the real-life world, so it’s ultimately about choosing which world to exist in.”  

After filming ended on Supergirl, Alcock went straight to work on a new indie film with director Daina Oniunas-Pusić, Thumb. She says it has parallels with Kara in that it “follows another story of an outcast trying to find her way in the world, although through this darkly comedic lens.” After that, she teamed up with Charli xcx and Hailey Benton Gates on a girl-trip-goes-bad horror, which she filmed in Japan with Takashi Miike. It is at yet untitled and “under wraps.” She says she’s still “in awe” at both experiences.  

Alcock thinks that all the characters she plays have similar touchstones. “They’re all these strong, very resilient women and I think that is definitely something I seek out,” she says. “I find those parts to be incredibly fulfilling to play.” Next, she continues, “I want to try everything. I would love to do more independent films. I would love to do more theatre. But ultimately, I just want to tell compelling stories. So whatever medium that presents itself in, I’m interested in doing it.” 

She lets out a huge jet-lagged yawn before apologizing. “I am definitely looking forward to a holiday,” she smiles, looking ahead to her upcoming vacation and a family reunion. Despite the tiredness, she is loving every moment of this whirlwind, racing towards the sun at light speed and all. “The reason I do my job is because I absolutely love acting and performing. And as long as I’m doing that, everything is okay.” 

Photographed by Austin Calvello

Styled by Christopher Campbell 

Written by Elizabeth Aubrey

Hair: Rena Calhoun at A-Frame Agency 

Makeup: Pati Dubroff at Forward Artists 

Nails: Yoko Sakakura at A-Frame Agency 

Flaunt Film: Logan Bik

Gaffer: Bono Melendrez

Style Assistant: Sophie Saunders 

Production Assistants: Ameen Kher and Eliot Correll