Milly Alcock to lead DCU film as Supergirl

Australian actress Milly Alcock, known for playing Princess Rhaenyra Targaryen in HBO’s House of the Dragon, has been cast as Kara Zor‑El/Supergirl in the DC Universe. The role was confirmed by DC Studios co‑chairmen James Gunn and Peter Safran after Alcock’s performance caught their attention. She filmed a self‑tape from Sydney during the pandemic, flew to Atlanta for testing, and was officially offered the part in early 2024.

The upcoming Supergirl film, directed by Craig Gillespie and scripted by Ana Nogueira, is based on the Tom King and Bilquis Evely comic miniseries Supergirl: Woman of Tomorrow. It is slated to open on June 26, 2026 in the United States, following a tag‑scene appearance at the end of last summer’s Superman kick‑off for the new DCU. Alcock has spoken about the pressure of joining a major franchise and her decision to ignore online trolling.

The production forms part of DC Studios’ broader plan to launch a new slate of interconnected superhero movies under Gunn and Safran’s leadership.