<i>Avengers: Doomsday</i>: Everything We Know So Far

With San Diego Comic-Con in full swing this July, more details of the upcoming Avengers films have been released. Though the next installment is over a year away still, fans are incredibly excited for what the MCU has in store.

Part of that excitement comes with the release of the new Fantastic Four film, which introduces the new Big Bad played by none other than Robert Downey Jr. Doctor Doom is coming and he is making worlds collide—worlds that the films have been setting up for over two decades.

Despite this epic threat, with a new batch of Avengers and Fantastic Four family members on the scene, things are bound to get pretty heroic. Here’s everything we know about Avengers: Doomsday so far.

The story is still a bit under wraps, but fans of the comics have a pretty good guess. Ultimate Comics: Doomsday was released in 2011 in several books and it follows the Fantastic Four working with other Marvel superheroes to prevent a powerful villain from destroying their timeline.

Cast announcements have pointed to this being the film’s premise, especially with Robert Downey Jr.’s return as Doctor Doom. The recent release of the new Fantastic Four movie, as well as actors from previous Marvel X-Men films slated to star, means we will likely see a mix from all the timelines/MCU franchises trying to take down Doom. And, since Doom looks exactly like Iron Man, it probably means that he is some alternate timeline version of Tony Stark who went very, very dark.

Seriously, who won’t be in this movie?

Aside from Downey Jr., other confirmed cast includes Rebecca Romijn as Mystique, Patrick Stewart as Professor X, Ian McKellen as Magneto, Alan Cumming as Nightcrawler, Kelsey Grammer as Beast, and James Marsden as Cyclops. In March 2025, Marvel confirmed more cast during a livestream, including Chris Hemsworth, Anthony Mackie, Danny Ramirez, Paul Rudd, Tom Hiddleston, Letitia Wright, Winston Duke, and Simu Liu.

Then there’s the Fantastic Four team confirmed to appear, with Pedro Pascal as Reed Richards, Vanessa Kirby as Sue Storm, Joseph Quinn as Johnny Storm, and Ebon Moss-Bachrach as Ben Grimm. Downey Jr. even made his first appearance as Doom in their movie in a mid-credits scene.

There are also big stars from amongst the Thunderbolts (or the New Avengers) to choose from, including Sebastian Stan as Bucky Barnes, Florence Pugh as Yelena Belova, David Harbour as Red Guardian, Wyatt Russell as U.S. Agent, Olga Kurylenko as Taskmaster, Hannah John-Kamen as Ghost, Julia Louis-Dreyfus as Valentina Allegra de Fontaine, and Lewis Pullman as Bob.

Avengers: Doomsday already has a release date: Dec. 18, 2026. It will be followed by a part two, Avengers: Secret Wars in December 2027.