While the world has come to know Downey mostly as the one and only Iron Man, in a different timeline, he could have been the infamous Fantastic Four villain.
In The Story of Marvel Studios: The Making of the Marvel Cinematic Universe, which was published in late 2022, the book casually dropped a quote from Favreau that "Marvel had already met with [Robert Downey Jr.] before... to play Doctor Doom."
It isn't confirmed alongside the quote, but it's assumed that it was for 2005's Fantastic Four.
Kevin Feige Confirms Downey Jr.'s Doctor Doom Talks
In their conversation, Favreau revealed how he remembered Marvel "had all met with [Robert Downey Jr.] already for like Dr. Doom," a statement that was met with a nod of acknowledgment from Feige himself:
"I remember that Robert had come in for a general on it and I remember you had all met with him already for like Dr. Doom or something on another project... I think he had come through on... like Fantastic Four... So everybody sort of knew who he was and I remember sitting down with the guy and I was like geez he just got... that spark in him and his eye, and he's ready. And that's when we were in your (Kevin Feige) office and we were pointing to his headshot and saying we got to try to figure this out."
This isn't the first time that Downey Jr.'s talks for Doctor Doom were revealed, but it is the only place where Kevin Feige acknowledged those discussions.
In his conversation with Feige, the director also shared that it wasn't until the leading man was cast that he "fully understood what the take was:"
"It wasn't really until we cast Robert [Downey Jr.] that I fully understood what the take was and once it was Robert... every decision became a lot easier."
Feige admitted that casting Downey Jr. as Tony Stark was "probably one of the greatest decisions in the history of Hollywood:"
"... I think that's probably one of the greatest decisions in the history of Hollywood and everybody has good days and bad days and I remember on later movies we'll talk about in 15th anniversary of those there were dark days and I would say, 'Robert, we wouldn't be in this mess if it wasn't for you' (laughs). Meaning we wouldn't have a studio if it wasn't for him or [Jon Favreau]."
The Doctor Doom That Never Was
While Robert Downey Jr. never got to put on the Doctor Doom set of armor, he instead got to become one of the biggest superheroes in all of pop culture—so everything worked out in the end.
Downey Jr. is a fantastic actor, so he'd undoubtedly make for an incredible Doctor Doom if given the chance.
With a Fantastic Four reboot on the way in the MCU, those beloved characters will finally be given another chance at stardom, this time in the hands of Marvel Studios. However, it remains a mystery if Doctor Doom himself will even appear in the 2025 film.
Sadly, it doesn't even look like Robert Downey Jr. will get to interact with anyone from the iconic family. A crossover like that is a much harder feat these days, as Tony Stark is dead in the MCU.
Though, with an event like Avengers: Secret Wars on the table and the Multiverse being a key focus, anything could happen. Maybe Marvel will even let Downey Jr. bring to life an alternate Doctor Doom—the one that never was.
Marvel Studios' Fantastic Four is set to hit theaters on February 14, 2025, while Avengers: Secret Wars is aiming for May 1, 2026.