Robert Downey Jr.'s first Doctor Doom appearance has reportedly been revealed – and it's not Avengers: Doomsday

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Robert Downey Jr.'s first Doctor Doom appearance has reportedly been revealed by a notable scooper – and it's not Avengers: Doomsday.

According to Jeff Sneider, Robert Downey Jr.’s Doctor Doom will first show up in a separate movie's post-credits scene or mid-credits scene, with Sneider then going on to speculate that it could be during 2025’s Fantastic Four.

The ex-Iron Man actor was unveiled as part of the Avengers: Doomsday cast during the Marvel SDCC panel. The members of Fantastic Four and Thunderbolts were also confirmed to be part of what was previously titled Avengers: The Kang Dynasty.

While it’s exciting news for those looking towards Marvel’s immediate future, we should exercise caution in this case. After all, Jeff Sneider’s track record has been good, yet inconsistent, in recent years.

He’s certainly called some major MCU news right – including that Harrison Ford was being lined up to play ‘Thunderbolt’ Ross as well as being among the first to confirm Fantastic Four’s casting months before it was made official – but not all of his scoops in the past have been verified or proven correct. Let’s take this one with a Hulk-sized pinch of salt for now as there’s no reason for Marvel to come out to confirm or deny the news.

Plans can, of course, change. But we certainly wouldn’t be surprised if Robert Downey Jr. shows up in Fantastic Four. The link between Reed and Doom is obvious, given their comic book history, but there’s the added eyebrow raise of Fantastic Four director Matt Shakman telling Collider that he’s had to keep the surprise casting under wraps "for a while."

Was Marvel just keeping the director in the loop – or is it something more? We’ll find out when Fantastic Four (starring Pedro Pascal, Vanessa Kirby, Joseph Quinn, and Ebon Moss-Bachrach) flies into cinemas on July 25, 2025.

For more, check out all the upcoming Marvel movies and shows on the way, as well as our guide to how to watch the Marvel movies in order.