Robert Downey Jr isn’t the real Doctor Doom in the MCU, according to fan theory
SDCCThe casting of Robert Downey Jr. as Doctor Doom has turned more than a few heads, but some fans are convinced it’s a red herring.
It was officially confirmed at San Diego Comic-Con 2024 that Robert Downey Jr. would make his long-anticipated return to the MCU in 2026’s Avengers: Doomsday.
The casting of the former Iron Man star, whose death was the exclamation mark that ended the legendary Infinity Saga, has sent fans into a tizzy.
Many fans are digging deep to try to find any excuse as to how the RDJ casting is not what it is at face value, and assuming that the goal is for some kind of massive twist. One Twitter user is convinced it’s all to hide the casting of another fan-favorite pick as the real Doom.
“My friend thinks Robert Downey Jr as Doctor Doom for Avengers: Doomsday is just a cover up for another actor to be revealed during the movie…Cillian Murphy?” user BLUERAYANGEL shared in a post on X.
The twist would be massive but not unprecedented for the MCU. Downey himself was in the first major MCU casting twist when Ben Kingsley’s Mandarin was revealed to be a fake in Iron Man 3.
As for Cillian Murphy, he’s managed to avoid superhero fare since appearing as Scarecrow in Christopher Nolan’s Dark Knight Trilogy. The Irish actor, now best known for his role alongside Downey in Oppenheimer, has long been a fan-favorite pick to play the sinister Dr. Doom, a scheming dictator who aspires for cosmic power.
Doom has been rumored to be sneaking his way into the MCU for years, but fans won’t have to wait too long. The character will officially debut in 2026’s Avengers: Doomsday (though one leaker has already claimed he’ll debut in The Fantastic Four: First Steps).
While you wait to find out if RDJ will be the Doom or he was just another trick to keep fans on the edge of their seats, check out our Deadpool 3 ending explainer or find all the Easter eggs in the movie with us.
You can also read about Deadpool & Wolverine’s jaw-dropping box office and look ahead to upcoming Marvel movies like Avengers Doomsday.