Robert Downey Jr Makes MCU Comeback as Dr Doom: How Iron Man Star Fits Into Avengers Doomsday | Explained

Robert Downey Jr is returning to Marvel Cinematic Universe (MCU) as Doctor Doom. He will be seen in Avengers: Doomsday (May 2026) followed by Avengers: Secret Wars (May 2027). The announcement was made during the Marvel panel in Hall H at the San Diego Comic-Con. The news has come as a massive surprise for Marvel fans. However, how will Robert Downey Jr — who once played Iron Man in the MCU — return as Doctor Doom? Let’s break down his MCU comeback.

Robert Downey Jr’s Farewell to Iron Man to MCU Return as Doctor Doom:

Robert Downey Jr had announced his retirement from the Marvel Cinematic Universe in 2019, with the release of Avengers: Endgame. The actor played the role of Iron Man, building a strong foundation for MCU. After playing the role of Tony Stark aka Iron Man for 10 years, RDJ took a bow in 2019. His character, Tony Stark performed the ultimate sacrifice to bring the 10-year-journey of his character and the MCU to a grand end.

Although Downey Jr had hung up his iron helmet, fans had always wished to see him return. In the recently released Deadpool & Wolverine, Ryan Reynolds also joked about his MCU return. He had fans guessing that RDJ might turn up but joked that he doesn’t do MCU cameos anymore.

So, it comes as a welcomed surprise that RDJ decided to return to MCU. Although not as Iron Man but as Doctor Doom. The actor will be seen in Avengers: Doomsday. The announcement was made at the San Diego Comic-Con on Saturday night. Anthony Russo, of the Russo Brothers, confirmed that the director duo will be helming the project and said that they envisioned one of the best actors to play Doctor Doom — Robert Downey Jr.

“If we’re going to bring Doctor Doom to the screen — he is one of the most complex characters, most entertaining characters in all of fiction. If we’re going to do this … then we are going to need the greatest actor in the world,” Anthony Russo said, as reported by The Hollywood Reporter.

Who is Doctor Doom, MCU Character Played by Robert Downey Jr?

For the unversed, Doctor Doom is a Fantastic Four villain. Introduced in Fantastic Four #5, in 1962, the character was created by Stan Lee and Jack Kirby. With the abilities to technopathy, perform black magic and sorcery, and having the strength of a superhuman, Doctor Doom is the main villain of the Fantastic Four: Story series in the comics.

Will Robert Downey Jr’s Doctor Doom Be Connected To Iron Man?

Here’s where it gets interesting. While at the time of reporting, the Russo Brothers have not revealed if Iron Man and Doctor Doom will be connected, it is safe to say that the two characters will stand distinctively. Avengers: Doomsday is likely to be set in a separate timeline as the one seen in the recent years.

Marvel Studios is working on The Fantastic Four: First Steps, the first Fantastic Four film under the banner after they acquired the rights to the comic book characters from 20th Century Fox. The title features new Fantastic Four cast members — Pedro Pascal, Vanessa Kirby, Joseph Quinn and Ebon Moss-Bachrach. Given the reboot, Marvel Studio is in all likelihood setting a new path for the next Avengers series, killing Kang as its central villain.

If that is the path they are going with, it gives room for Robert Downey Jr to explore another character in the MCU. There are two possiblities here. First, Downey Jr could play a varient of Iron Man/Tony Stark who learned black magic to fight against Thanos in one of the timelines. The superpowers of the magic turned him into Doctor Doom.

Another possiblity could be that Doctor Doom might just have Downey Jr’s face and will not have any connection with Iron Man. In both cases, Marvel is likely to explore a new timeline, like they did with Deadpool & Wolverine, which will not overlap Tony Stark’s death in Avengers: Endgame with the events that are set to take place in Avengers: Doomsday.