Given that he is the Fantastic Four's foremost rival, I'm convinced that Robert Downey Jr. will appear as the Avengers: Secret Wars.
His arch-rival, Reed Richards, will meanwhile make his MCU debut in The Fantastic Four: First Steps. It was revealed relatively early on that Doctor Doom will appear despite Matt Shakman's claims.
The Fantastic Four: First Steps Director Addressed Whether Doctor Doom Appears
Matt Shakman Casts Doubt On Doom's Debut
While on the media circuit promoting The Fantastic Four: First Steps, director Matt Shakman spoke to Empire Magazine. In the interview, a snippet of which was posted to ComicBookMovie, Shakman addressed the prevailing theories that Doctor Doom will make his MCU debut at some juncture in The Fantastic Four: First Steps, with the post-credits scene being most likely. His response seems to put the issue to bed entirely, as he resolutely stated:
Doom is not a part of my film, and therefore not a part of my purview.

Why The Fantastic Four: First Steps' Villain Is Galactus Instead Of Doctor Doom Explained By Director
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Shakman's comments raise some important questions. Presuming he is not saying this to misdirect audiences (a tactic that is not beyond Marvel Studios, it should be stated), then we are forced to wonder if the Fantastic Four have even encountered Doom at this point in their careers. With the character being so inexorably tied to the titular team, this would be a risky move from Marvel Studios, to say the least. Alternatively, I believe Shakman's short comment suggests that while Doom isn't part of his purview, he could still appear in his movie.
Why I'm Convinced Doctor Doom Could Still Appear In The Fantastic Four: First Steps
The Post-Credits Scene Might Not Technically Be A Part Of Shakman's Film
I think Thunderbolts* shows us how Doctor Doom can fall outside Matt Shakman's purview but still be a part of the movie in another way. While Thunderbolts* was largely self-contained, to the extent that New York's many superheroes did not respond to the looming threat of the Void in the streets of Manhattan, the Thunderbolts* post-credits scene connected it directly to Avengers: Doomsday as the Fantastic Four's spaceship was seen entering Earth's orbit from another universe. The scene looked decidedly different from the rest of the movie because it was directed by the Russo brothers.
If Doctor Doom were to appear in another post-credits scene directed by the Russos, then Shakman is still correct in stating that Doom is not part of his purview.
The Russo brothers were revealed to be directing Avengers: Doomsday and Avengers: Secret Wars at the same time as the Avengers: Doomsday title and Robert Downey Jr.'s return were announced. Given that Thunderbolts* was directed by Jake Schreier, the Thunderbolts* post-credits scene isn't technically part of his film, and I think the same could be said for Matt Shakman and The Fantastic Four: First Steps. If Doctor Doom were to appear in another post-credits scene directed by the Russos, then Shakman is still correct in stating that Doom is not part of his purview.
Why Doctor Doom Needs To Appear In The Fantastic Four: First Steps
The MCU Is Running Out Of Time To Debut The Multiverse Saga's Arch-Villain
The necessity of Doctor Doom's debut in The Fantastic Four: First Steps extends beyond the fact that he is Reed Richards' nemesis. The Fantastic Four: First Steps is the penultimate movie before Avengers: Doomsday, and audiences haven't heard so much as a peep from the Multiverse Saga's arch-villain until now. By contrast, at the parallel point in the Infinity Saga, Thanos appeared three times, mostly in MCU post-credits scenes, but also as a secondary villain in the main bulk of the movie in Guardians of the Galaxy.
Thanos appeared in the post-credits scenes of The Avengers and Avengers: Age of Ultron, which may indicate why the Avengers-deprived Multiverse Saga has yet to tease Doctor Doom.
While The Marvels and Thunderbolts* directly connected to Avengers: Doomsday with their post-credits scenes, the arch-villain was notably absent. While it could be argued that incursions, which are brought about through multiversal meddling, are perhaps a bigger threat than Doom, the more tangible villain would be severely underserved if not teased in either The Fantastic Four: First Steps or Spider-Man: Brand New Day, or both. I'm hopeful, as filming for Avengers: Doomsday is well underway, which makes filming a Doom-led post-credits scene for The Fantastic Four: First Steps entirely feasible.

The Fantastic Four: First Steps
- Release Date
- July 25, 2025
- Runtime
- 130 Minutes
- Director
- Matt Shakman
- Writers
- Jeff Kaplan, Josh Friedman, Ian Springer, Eric Pearson, Stan Lee
- Producers
- Jamie Christopher, Kevin Feige, Louis D'Esposito, Tim Lewis
Cast
- Reed Richards / Mr. Fantastic
- Vanessa KirbySue Storm / The Invisible Woman
- Johnny Storm / Human Torch
- Ebon Moss-BachrachBen Grimm / The Thing
- Franchise(s)
- Marvel Cinematic Universe
MCU Movies
Sources: Empire Magazine/ComicBookMovie