The Secret Is Out: Marvel Fans Finally Know Who Sadie Sink Plays in ‘Spider-Man: Brand New Day’

One of the biggest mysteries surrounding Spider-Man: Brand New Day (2026) has finally been answered.

Ever since Sadie Sink was announced as part of Tom Holland’s next Spidey adventure, Marvel fans have been desperate to know which character the Stranger Things star would bring to the Marvel Cinematic Universe.

Marvel Studios and Sony Pictures deliberately kept Sink’s role secret throughout the film’s marketing campaign, creating months of speculation and fan theories.

Among the most popular theories were X-Men favorites Jean Grey and Rachel Summers, especially as Marvel continues building toward its long-awaited mutant storyline.

The upcoming Avengers: Doomsday (2026) has already confirmed the return of several actors from Fox’s X-Men franchise, making those possibilities even more likely.

However, after the movie’s world premiere, many Marvel fans finally have their answer.

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Sadie Sink’s Spider-Man Role Has Been Revealed

The film had its world premiere at the Dolby Theatre in Hollywood on Monday. While early attendees have now had the chance to see Peter Parker’s latest adventure, Marvel and Sony are still protecting the movie’s biggest plot details until audiences worldwide can experience it.

With that said, musician Steve Lacy, who has a song for the film titled “oh yeah?,” did spoil the identity of Sink’s character on the red carpet.

Social media reactions have begun online; however, the embargo lifts later today, July 28, meaning full critic reviews for the film are not yet available.

Directed by Destin Daniel Cretton, Spider-Man: Brand New Day continues Peter Parker’s story after the emotional events of Spider-Man: No Way Home (2021).

Tom Holland returns as Spider-Man, with Zendaya reprising her role as MJ and Jacob Batalon returning as Ned Leeds.

The film also stars Jon Bernthal as Frank Castle/The Punisher, Mark Ruffalo as Bruce Banner/Hulk, Tramell Tillman as Bill Metzger, and Michael Mando as Mac Gargan/Scorpion.

The new film also arrives at an important moment for the MCU. Just months later, Marvel Studios will release Avengers: Doomsday, bringing together heroes and villains from across the franchise.

With Peter Parker entering a new era and Marvel preparing for its next massive crossover, Spider-Man: Brand New Day is set to be one of the studio’s biggest releases of 2026.

Spider-Man: Brand New Day swings into theaters on July 31, 2026.

Who do you think Sadie Sink is playing in Spider-Man: Brand New Day? Share your theories with us in the comments below!