James Gunn Praises Milly Alcock as His Best Casting Ever for Supergirl

DC Studios co-head James Gunn is known for his sharp eye when it comes to casting, but his latest pick has him more excited than ever. In a recent interview on The Howard Stern Show, Gunn declared that casting Milly Alcock as Supergirl “might be the best bit of casting I’ve done in my entire life”. That’s high praise from the man behind hits like Guardians of the Galaxy and The Suicide Squad.

Quick read:

• James Gunn called Milly Alcock “absolutely stunning” as Supergirl.
• He said she “might be the best bit of casting” he’s ever done.
• Her debut scene involves a drunken entrance and bonding with Krypto.

Milly Alcock’s Supergirl Debut Is Already Making Waves

Alcock, best known for her role as Rhaenyra Targaryen in House of the Dragon, made her DCU debut in a surprise cameo at the end of Gunn’s Superman reboot. In the scene, she drunkenly stumbles into the Fortress of Solitude and fusses over Krypto the Superdog—an unexpected but memorable entrance.

Her solo film, Supergirl, is currently in post-production and slated for release on June 26, 2026. Directed by Craig Gillespie (I, Tonya, Cruella) and written by Ana Nogueira, the film is described by Gunn as “a big science fiction epic.” With a supporting cast that includes Matthias Schoenaerts and Emily Beecham, expectations are sky-high.

Gunn’s Endorsement Sets the Tone for DC’s Future

Gunn’s glowing endorsement of Alcock’s performance signals a major shift in how Supergirl will be portrayed—gritty, emotionally complex, and far from the traditional mold. He called her performance “absolutely stunning,” adding even more weight to the anticipation surrounding the film.

With Gunn’s track record and Alcock’s rising star power, Supergirl could be the defining superhero film of the decade. DC fans, get ready—this Kryptonian is about to take flight.

Read next: House of the Dragon’s Milly Alcock sets DCU ablaze with Superman cameo