Why Milly Alcock’s Supergirl already feels different from Superman

James Gunn has offered the first official glimpse of Milly Alcock as Supergirl, signalling a clear tonal shift for the DC Universe as the character prepares for her standalone film.

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The short clip, released ahead of Supergirl’s full trailer drop later this week, shows the House of the Dragon breakout star in a grounded, casual look rather than in her superhero suit. Wearing a coat, jeans and sunglasses, Alcock’s Kara Zor-El is positioned as more distant and self-contained than her famous cousin, Kal-El.

Best known for her breakthrough role in HBO’s House of the Dragon, Alcock has since expanded her screen presence with projects including the recent drama series Sirens, helping cement her transition from breakout star to leading actor.

Gunn has previously confirmed that Supergirl’s story will differ sharply from Superman’s, both in tone and structure. While Superman is being framed as a hopeful, earth-bound hero, Supergirl’s journey is set to unfold as a space-driven adventure.

“Supergirl especially is a space adventure,” Gunn said earlier. “It is more in the lane of Guardians. Lanterns is its own thing. There is a bigger world we are building with all these different pieces and they intersect in different ways.”

Alcock has already entered the DC Universe through upcoming appearances connected to Superman, followed by a brief role in Peacemaker season two. Her solo film will further expand the interlinked world being shaped by Gunn and DC Studios co-head Peter Safran.

The director has also singled out Alcock’s casting as one of his strongest decisions to date, previously describing it as “might be the best I have ever done”.

Supergirl is scheduled for theatrical release on 26 June 2026 and will form a key part of DC’s rebooted cinematic slate.