Milly Alcock spent years building a career in Australian television and film before House of the Dragon turned her into one of HBO’s breakout stars. Now she’s stepping into an even bigger role: Kara Zor-El, in DC Studios’ upcoming Supergirl film.
The shift from playing Rhaenyra Targaryen to playing Superman’s cousin happened faster than Alcock expected, and by her own account, it left her a little stunned.
How Gunn Found His Supergirl
When James Gunn and Peter Safran took over DC Studios, they wanted a Supergirl who broke from the usual mold. They found their template in Tom King’s comic series Supergirl: Woman of Tomorrow, which portrays Kara as harder-edged and more emotionally raw than past versions of the character.
Gunn had a specific type in mind for the role: someone with a punk energy who could play a Supergirl that felt battle-worn rather than wholesome. He remembered an actress who fit the part, though he couldn’t place her name at first. He knew where he’d seen her: House of the Dragon.
“She was exactly the kind of person we were looking for,” Safran said. “Someone who could bring a fresh energy to the character and show audiences a side of Supergirl they haven’t seen before.”
A Self-Tape, a 24-Hour Flight, and a Text Message
Alcock learned about the role through a self-tape request for an undisclosed project. She sent one in without knowing much about what she was auditioning for.
Ten days after a screen test in Atlanta, which meant a 24-hour flight from Sydney, her phone buzzed. Gunn didn’t call. He texted her a news article confirming she’d been cast as Supergirl, and she found out from the headline before she’d had time to process anything.
“I remember thinking, ‘This is insane. What have I gotten myself into?'” she said.
She was on another long flight within days to shoot her brief appearance in Superman.
A Darker Origin Story
Where Superman’s optimism comes from being raised by loving parents, this Supergirl carries different baggage. Kara watched Krypton get destroyed and lost everyone she knew before she ever reached Earth. That history shapes a character who’s angry, grieving, and still figuring out what she’s supposed to do with her life.
The film follows her on an intergalactic story that includes Krypto the Superdog and a woman out for revenge against a dangerous villain. Safran describes it as something other than a standard superhero movie.
“It’s a unique story with a very different emotional core,” he said. “Even people who don’t normally watch superhero movies are going to find something to connect with.”
Alcock Sees Herself in the Character
Alcock didn’t expect to relate to a superhero, but Kara’s struggle with identity and grief hit close to home for her.
“Kara reminded me a lot of myself,” she said, describing a character trying to hold onto who she is while everyone around her pulls her in different directions. Alcock has been dealing with a version of that pressure herself as her own profile has grown.
Adjusting to Fame
Alcock got into acting partly because it let her vanish into other people. Supergirl is doing the opposite: making her one of the most recognizable new faces in a major franchise.
She’s now based in London, working through what it means to be known by strangers.
“It’s exciting, but it’s also terrifying,” she said, adding that the attention feels exposing for someone who’d rather let her work do the talking.
Early Buzz
Alcock’s screen time in Superman ran only a few seconds, but it was enough to get people talking. Safran said audience reaction afterward focused heavily on wanting to see more of her Supergirl.
“She’s authentically tough and fearless,” he said. “That quality comes across naturally.”
Behind the Camera
Craig Gillespie is directing, bringing experience from I, Tonya and Cruella, both built around messy, complicated women. That background lines up with a Supergirl story rooted in emotional weight rather than spectacle alone.
Getting Used to Being a Toy
One part of the job Alcock still hasn’t fully wrapped her head around: action figures. She brought it up with Superman star David Corenswet, who told her he loved the idea of merchandise modeled after him.
She didn’t share the enthusiasm.
“Why would someone want a toy with my face on it?” she said, laughing.
What’s Next
DC Studios is building a new cinematic universe around films like this one, and Supergirl carries real weight for where the franchise goes from here. Alcock, for her part, says she’s still just an actress who likes telling stories. She’s doing it now in a cape.
George Mensah is a journalist covering global politics, international conflicts and economic developments for clicxpost. He specializes in breaking news analysis and geopolitical reporting.