Robert Downey Jr. teases Iron Man and Doctor Doom roles for Avengers: Doomsday promotion

A new social media post from Robert Downey Jr. has drawn renewed attention to Avengers: Doomsday and its gradually intensifying promotional run. The update, shared on Instagram, has fueled ongoing speculation about Downey’s involvement in the upcoming Marvel film.

The actor’s casting as Doctor Doom in Avengers: Doomsday has already sparked widespread theories about dual roles or multiversal appearances. Comments on Downey’s post included predictions about Iron Man’s potential comeback in future MCU installments, including Secret Wars.

This is not the first time Downey has hinted at his Doctor Doom portrayal. Earlier this year, he shared various themed posts tied to the character, including a DOOM #1 (2024) comic image labeled as part of his “Doom workstation essentials,” a Valentine’s Day photo featuring a Doom mask filled with chocolates, and a Mother’s Day post showing Susan Downey styled as Sue Storm while her mother knits Doctor Doom’s costume.

Avengers: Doomsday, directed by Anthony and Joe Russo, is scheduled for release on December 18, 2026. The cast includes Downey, Chris Hemsworth, Vanessa Kirby, Joseph Quinn, and Ebon Moss-Bachrach. According to Collider, Marvel intends to debut the first trailer on December 19, 2025, ahead of screenings of Avatar: Fire and Ash.

Marvel Studios has kept production details closely guarded, with no notable set images or footage emerging so far.