Robert Downey Jr. is officially returning to the Marvel Cinematic Universe, but not as Tony Stark. Marvel Studios confirmed he will step into the role of Victor Von Doom in Avengers: Doomsday. The casting is already being called one of the most daring moves in superhero cinema. The film is set to arrive in theaters on December 18, 2026.
The reveal happened at San Diego Comic-Con 2024 in dramatic fashion. Downey appeared on stage in full Doom armor, pulled off the mask, and told the crowd, “new mask, same task.” Kevin Feige later explained that they needed “the greatest actor in the world” to take on the depth and complexity of Doctor Doom.
At Disney’s 2026 Merchandise Expo in China, Marvel dropped the first official synopsis. It teased Doom as a genius of science and a master of dark magic who ignites a crisis across the entire multiverse. Industry insiders believe the Russo Brothers are drawing from the famous Rabum Alal storyline, where Doom grows powerful enough to threaten whole universes.
Fans also got an early look at Downey’s Doom through new promotional artwork and a massive light show in Shanghai. The armor design leans into a medieval style with chainmail, intricate metalwork, and glowing runes that hint at his sorcery. One sequence even showed Doom holding a skeleton, a moment that many recognized as a nod to Secret Wars where Doom kills Thanos. This points to a storyline centered on domination rather than salvation.
The film’s cast announcement only added to the excitement. During a record-breaking livestream in March 2025, Marvel confirmed the return of Chris Hemsworth as Thor, Anthony Mackie as Captain America, and Tom Hiddleston as Loki. The movie will bring together the Avengers, Fantastic Four, X-Men, and New Avengers in one massive lineup. Pedro Pascal will appear as Mister Fantastic, Vanessa Kirby as Sue Storm, and original X-Men icons Patrick Stewart, Ian McKellen, Alan Cumming, Rebecca Romijn, and James Marsden are all coming back.
Director Anthony Russo revealed that Downey is throwing himself into the role. He has been helping shape Doom’s backstory, working on costume ideas, and exploring the character’s deeper layers. Russo explained that Downey thrives on complex roles and sees Doctor Doom as a chance to create something entirely different from Tony Stark. Both are brilliant inventors with huge egos, but this new performance is expected to deliver a villain unlike anything the MCU has seen before.
