Milly Alcock is best known as Princess Rhaenyra Targaryen on 'Game of Thrones' spinoff 'House of the Dragon'

DC Studios bosses James Gunn and Peter Safran have officially found their Supergirl for Warner Bros.’ Supergirl: Woman of Tomorrow.

Milly Alcock, who plays Rhaenyra Targaryen in HBO’s Game of Thrones prequel series House of the Dragon, is set to star as Superman's cousin Kara Zor-El, confirmed The Hollywood Reporter.

Last week, the role was tied between Alcock and Meg Donnelly as screen test took place in Atlanta, with Gunn and Safran in attendance.

Alcock’s character will be first appearing in Superman: Legacy, which will begin filming in spring this year.

Gunn took to Instagram on Tuesday to share his thought on the new addition to the DC universe.

Milly is a fantastically talented young actor, and I’m incredibly excited about her being a part of the DCU,” he wrote in the caption. “Yes, I first became aware of her in House of the Dragon but I was blown away by her varied auditions and screen tests for #Supergirl. She embodies Kara as envisioned by @tomking_tk, @bilquis and Ana Nogueira.”

Superman: Legacy stars David Corenswet as Superman. Nicholas Hoult as Lex Luthor, Rachel Brosnahan as Lois Lane, Nathan Fillion as Green Lantern, Isabela Merced as Hawkgirl, Edi Gathegi as Mister Terrific, María Gabriela de Faría as The Engineer, Anthony Carrigan as Metamorpho, Skyler Gisondo as Jimmy Olsen and Sara Sampaio as Eve Teschmacher.