Robert Downey Jr. Returns as Doctor Doom in Marvel’s Avengers: Doomsday

Robert Downey Jr. is set to re‑enter the Marvel Cinematic Universe, not as Tony Stark but as the villain Victor von Doom, in the upcoming film Avengers: Doomsday. The movie is slated for worldwide theatrical release on 18 December 2026 and is being directed by the Russo brothers, who also helmed Infinity War and Endgame.

In interviews Downey and co‑director Joe Russo said the film is designed to avoid the “post‑Endgame slump” that has affected several recent MCU releases. Russo described it as the most emotionally complex and mature Avengers installment to date, while Downey emphasized that its structure and ensemble of characters constitute the “only antidote” to disappointing audiences after Infinity War and Endgame.

Leaked footage has revealed a large‑scale crossover battle in which Doctor Doom commands a Sentinel army against the X‑Men, providing the clearest look yet at the film’s central threat. The leak shows heroes such as Thor, Captain America, Shang‑Chi, and members of the X‑Men and Fantastic Four confronting the Sentinels, underscoring the movie’s ambitious multiverse scope.