Sadie Sink ‘Spider-Man’ Role Explained: Her ‘Brand New Day’ Character

Sadie Sink has been booked and busy since wrapping Stranger Things, and MCU fans are convinced they know what character she’s playing in Spider-Man: Brand New Day. The actress and Marvel Studios have remained tight-lipped about her role, but rumors about her casting pointed to a possible connection to the MCU’s X-Men.

During a January 2026 interview with Jimmy Fallon, Sadie said it’s been “torture” hiding the details of her role. Adding more fuel to the fire were the fan theories that spread online, which helped her learn that she had actually been cast in Brand New Day.

“I found out through online theories. Like, before I got cast in Spider-Man, like, there was speculation online that said, ‘Sadie Sink is going to be in the new Spider-Man.’ I was like, ‘Hmm? I am?'” the Whale star said, before adding, “And sure enough, two days later, they asked me to do it. So yeah, those theories, there’s sometimes some truth to it.”

As for the character she’s playing, Sadie acknowledged that there’s been “so much speculation” about it and added, “I feel like there’s a new character every week,” referring to fan theories.

So, who does Sadie play in Spider-Man: Brand New Day? Here, Hollywood Life has compiled everything we know so far about her character and involvement in the film.

Sadie Sink found out she got cast in @Spider-Man Movie: Brand New Day just like the rest of us 🤣 #FallonTonight #TonightShow #SadieSink #SpiderMan #JimmyFallon

What Is Sadie Sink’s Role in Spider-Man? Brand New Day Character Explained

Rumors have circulated that Sadie could be playing the role of Jean Grey in Spider-Man: Brand New Day, but neither she nor anyone from Marvel has addressed the rumors.

Mark Ruffalo‘s Bruce Banner, a.k.a The Hulk, appears in the 2026 movie as Dr. Banner, and Peter approaches him with a question about DNA mutations.

“If DNA is mutating, could it be enormously dangerous?” Bruce asks in the trailer.

Who Is Jean Grey in Spider-Man?

The character Jean Grey is a mutant, and, as seen in the Brand New Day trailer, it looks like Tom Holland‘s Peter Parker’s Spidey senses will undergo a mutation.

Fans were convinced they caught a quick glimpse of Sadie in the teaser clip, but whoever the character is appears with their back turned.