Kathryn Newton is returning to the Marvel Cinematic Universe in Avengers: Doomsday after starring in 2023’s Ant-Man and the Wasp: Quantumania.
The Ready or Not 2: Here I Come star will reprise her role of Cassie Lang in the Marvel film set to be released on December 18, 2026.
Newton made the announcement on her Instagram, revealing a mini director’s chair with her name, a nod to the way the studio confirmed the actors participating in the ensemble superhero movie.
“And it’s tiny because Cassie Lang gets tiny,” Newton said in the video. “She’s small, but sometimes she’s big. It depends what’s happening.”
Newton then used the chair to set her Avengers cap on. In the video, she then leaves the trailer, and a team of hair and makeup artists awaits her to give her some final touchups before filming her next scene.
Cassie will join her father, Scott Lang, in Avengers: Doomsday, with Paul Rudd reprising his role. Other actors confirmed for the film include Robert Downey Jr., Pedro Pascal (Mister Fantastic), Chris Hemsworth (Thor), Anthony Mackie (Captain America), Vanessa Kirby (Susan Storm), Florence Pugh (Yelena), Tenoch Huerta (Namor), Simu Liu (Shang-Chi), Sebastian Stan (Bucky Barnes), Letitia Wright (Black Panther), Ebon Moss-Bachrach (Thing) and Kelsey Grammer (Beast).
The film also stars Lewis Pullman (Sentry), Danny Ramirez (Joaquín Torres / Falcon), Joseph Quinn (Johnny Storm), David Harbour (Red Guardian), Winston Duke (M’Baku), Hannah John-Kamen (Ghost), Tom Hiddleston (Loki), Patrick Stewart (Charles Xavier / Professor X), Ian McKellen (Magneto), Alan Cumming (Nightcrawler), Rebecca Romijn (Mystique), James Marsden (Cyclops), and Channing Tatum (Gambit).

Kathryn Newton returns to MCU
