Meet Milly Alcock, who plays Supergirl in the upcoming DC Universe film

Following her breakout role as the young Rhaenyra Targaryen in House of the Dragon, a prequel to Game of Thrones, Milly Alcock is preparing to debut in yet another major franchise as she steps into the titular role of Supergirl in the upcoming film.

Set to premiere on June 26, the DC film also stars David Corenswet – reprising his role as Superman – and Aquaman star Jason Momoa.

Before landing the role of Supergirl, Alcock opened up in an interview with Vanity Fair, saying she had sworn off big franchises after House of the Dragon, but then started to panic when auditions dried up after she starred in Netflix’s Sirens.

“I was so s***‑scared that my life was over at 22,” the actress told Vanity Fair. So when the audition for Supergirl came along, the 26-year-old says, “I kind of bullied myself into it.”
Here’s everything to know about Milly Alcock, the new Girl of Steel.
She dropped out of high school to act

Born in Sydney in April 2000, Milly Alcock was raised by a single mother who worked as a nanny. Growing up, Alcock idolised Australian actors including Cate Blanchett, Sarah Snook and Heath Ledger. She struggled with school and at the tender age of 13, started cold-calling talent agencies in hopes of landing herself an audition. Her first ever role was as an extra in a 2014 episode of the Australian TV romcom drama Wonderland.
During her senior year of high school, Alcock landed the lead role in the Australian comedy-drama series Upright, and dropped out of school to pursue acting. Her mother was supportive of her decision, per Vanity Fair. “My mother instilled this blind confidence within me: ‘If those idiots can do it, why can’t you?’ Her words, not mine,” Alcock told the magazine. “It just lit a fire under my a***.”
She faced backlash for calling out fan behaviour

Alcock rose to stardom when she landed the role of 15-year-old Rhaenyra Targaryen in House of the Dragon in 2022, but her new-found fame came with sometimes unsavoury comments from fans of the series.
“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,” the young actress told Vanity Fair.
Alcock’s comment, published in March, quickly garnered negative attention from fans of the Game of Thrones and DC franchises. “Your movie isn’t even out and you’re already a victim of nothing happening to you – shut the f*** up,” one comment read, per the Hollywood Reporter. Another said, “They know their movie’s gonna suck; we know they’ll blame men as always.”
Who is Milly Alcock dating?

Alcock hard-launched her relationship with boyfriend Jo Powell in an Instagram post in June 2025. Powell works as a chef in London.
The couple made their red carpet debut at this year’s Baftas in February, and frequently post each other on their Instagram.