Robert Downey Jr.'s Doctor Doom Could Make His Debut Sooner Than Marvel Fans Think

Robert Downey Jr.'s Doctor Doom might make his official Marvel Cinematic Universe debut in the upcoming "The Fantastic Four" reboot, according to Hollywood blog TheInSneider. Downey Jr.'s polarizing return to the MCU was announced at San Diego Comic-Con last week, shocking fans and industry leaders alike who had been speculating for months about who would replace Jonathan Majors as the new Phase 6 big bad. Now, writer Jeff Sneider claims that Downey Jr. will actually appear earlier than expected, making his introductions in the post or mid-credit scene of the new "Fantastic Four" film.

Studios have yet to confirm this tidbit as more than rumor, but it's something /Film has been hearing, too, and it would make a lot of sense. Newly retitled "The Fantastic Four: First Steps" will mark the beginning of a new phase of superhero flicks from the ultra-popular franchise, and will lead into a two-part "Avengers" storyline — the first since 2019's "Avengers: Endgame." Victor Von Doom needs to make an entrance somehow, and a big mid-or-post credits moment is a classic Marvel way to do that. Plus, "Fantastic Four: The First Steps" director Matt Shakman told Collider he'd "had to keep [Downey's MCU return] secret for a while," something that would be necessary if the actor participated even tangentially in the movie he's making.

Downey's return to the franchise comes at a crucial time for superhero films, which seem to be in decline after a full decade of pop cultural and box office dominance. The MCU hasn't felt quite the same since five years ago, when "Endgame" capped off a number of story arcs that were a dozen-plus movies in the making, and while several projects since then have introduced fresh-faced, compelling heroes, Marvel ultimately chose to go back to the same money-making well with the Downey Jr. casting choice. The actor apparently had a long list of negotiables to get back on board, with Variety reporting that he even chose Joe and Anthony Russo personally as the directors of "Avengers: Doomsday" and "Avengers: Secret Wars."

Popular speculation has so far assumed that Downey's Doom will be some sort of Tony Stark variant, a detail InSneider's Jeff Snyder says aligns with an encrypted email he apparently received with the casting scoop. Given how brief and secretive most post-credit scenes are, this news, if accurate, is likely spoiling something that Marvel would never advertise ahead of the film's release anyway. Still, with so much about "Fantastic Four" still under wraps, fans won't know how or why Doom will pop up until it actually happens.

Before fans get a peek at the new Doctor Doom, they'll first have to watch the remainder of Phase 5, which will include "Captain America: Brave New World," "Thunderbolts," and Marvel TV shows including "Agatha All Along" and "Daredevil: Born Again." Will Downey's Doom save the MCU or just embody everything that's wrong with it? We'll find out soon enough: "The Fantastic Four: First Steps" hits theaters on July 25, 2025, potentially with a Doom cameo included.