For months, Marvel fans have been trying to figure out one of the biggest mysteries surrounding Spider-Man: Brand New Day (2026): who exactly is Sadie Sink playing in the new film?Since the Stranger Things star was announced as part of Tom Holland’s fourth solo Spider-Man outing, Marvel Studios and Sony Pictures have kept her role hidden, sparking countless theories about which character she could be bringing to the Marvel Cinematic Universe (the MCU).Credit: Marvel Studios / Sony PicturesAmong the most discussed possibilities have been major Marvel Comics characters, including X-Men favorites such as Jean Grey and Rachel Summers.With Marvel continuing to expand its mutant roster (several actors from Fox’s X-Men films have returned for the upcoming ensemble film Avengers: Doomsday), many fans have wondered whether Sink could be connected to the franchise’s long-gestating “Mutant Saga.”Credit: Marvel StudiosSadie Sink’s Character Has Been RevealedOthers have speculated that she could be taking on a character from Spider-Man’s own comic book history, with the mystery becoming one of the biggest talking points surrounding Spider-Man: Brand New Day.Now, with the movie’s red carpet premieres taking place ahead of release, for many—those fortunate enough to attend the events—the wait to learn more about Sink’s role is over.Credit: Marvel Studios / Sony PicturesWhile premiere events allow select attendees, including cast members, filmmakers, press, and invited guests, to experience the movie ahead of the public release, Marvel and Sony have continued to keep the film’s biggest surprises under wraps.Now, the film’s first reactions are in following the world premiere at the Dolby Theater in Hollywood on Monday night. Although full critic reviews are embargoed until later today, July 28 (the film is released in theaters on July 31), social media reactions have started to appear online.Credit: Sony Pictures/Marvel StudiosRelated: Confirmed: Two Different Versions of ‘Spider-Man: Brand New Day’ Officially Releasing in TheatersSpider-Man: Brand New Day Arrives July 31Directed by Destin Daniel Cretton, Spider-Man: Brand New Day marks the next chapter in Peter Parker’s story following the events of Spider-Man: No Way Home (2021), which left him alone after the world forgot his identity.Here’s the official synopsis from Marvel:It’s a BRAND NEW DAY for Peter Parker. Fighting crime full-time as Spider-Man in a world that doesn’t remember him—and the pressure of seeing his old friends move on without him—sparks a change in Peter he may not have the power to control. But that transformation might also be the only thing that can stop a shocking new threat to the city and those he loves—a powerful villain no one can even see.Tom Holland returns as Peter Parker, with Zendaya reprising her role as MJ and Jacob Batalon returning as Ned Leeds. The film also features Jon Bernthal as Frank Castle/The Punisher and Mark Ruffalo as Bruce Banner/Hulk, alongside Sadie Sink in her mysterious role.The film also stars Tramell Tillman as Bill Metzger, and Michael Mando as Mac Gargan/Scorpion.Spider-Man Leads Into Avengers: DoomsdaySpider-Man: Brand New Day arrives at a major point in the MCU, with Peter Parker’s fourth solo adventure coming shortly before Marvel Studios’ next massive crossover event.Avengers: Doomsday will arrive in December 2026 and bring together an enormous lineup of heroes and villains, including Robert Downey Jr. as Victor von Doom/Doctor Doom, Chris Hemsworth as Thor, Anthony Mackie as Captain America, Pedro Pascal as Reed Richards/Mister Fantastic, and several returning characters from across Marvel history.Spider-Man: Brand New Day swings into theaters on July 31, 2026.Remember to avoid spoilers for Sadie Sink’s character until you see the movie!Who do you think Sadie Sink is playing in Spider-Man: Brand New Day? Share your theories with us in the comments below!The post Sadie Sink’s ‘Spider-Man: Brand-New Day’ Character Has Finally Been Revealed Ahead of Release appeared first on Inside the Magic.