TMDb/Supergirl: The Making of Celebrity Supergirl takes flight! See Milly Alcock as Kara Zor-El in action-packed new footage. In theaters June 26. April 15, 2026 AceShowbiz - Milly Alcock and Jason Momoa joined DC Studios co-head Peter Safran onstage at CinemaCon to promote their upcoming film Supergirl, set for release on June 26. The Warner Bros. presentation showcased an extended scene from the movie directed by Craig Gillespie. Milly Alcock stars as Kara Zor-El, the cousin of Superman, who was first introduced in last summer's Superman film, portrayed by David Corenswet.