Is Hayley Atwell returning in Avengers: Doomsday? Comic-Con finally has the answer

Hayley Atwell joins Avengers: Doomsday cast as Ryan Reynolds surprises fans in a new Deadpool costume at Comic-Con

Marvel Studios delivered one of the biggest moments of San Diego Comic-Con 2026 by officially confirming that Hayley Atwell will return as Peggy Carter in the upcoming Avengers: Doomsday.

The announcement during the Hall H presentation ends months of speculation that the actress would reprise her fan-favourite Marvel role in the highly anticipated MCU blockbuster, scheduled for release on December 18, 2026.

Atwell’s return had been widely rumoured following reports that she would appear in the multiverse-focused film. Her confirmation has reignited fan theories about Peggy Carter’s role, with many speculating whether she will continue as the founder of S.H.I.E.L.D. or return as Captain Carter, the alternate-universe superhero previously seen in Doctor Strange in the Multiverse of Madness.

The panel also featured an unexpected appearance from Ryan Reynolds, who attended in the audience wearing a new denim-themed Deadpool costume, jokingly dubbed a “Canadian tuxedo” version of the antihero’s suit. While the appearance sparked fresh rumours that Reynolds could feature in Avengers: Doomsday, Marvel did not announce any involvement for the actor in the film.

Reynolds has previously hinted that ideas for Deadpool 4 and another Marvel team-up project are in development, but no official announcements have been made.

Marvel also unveiled a new Avengers: Doomsday poster during the presentation while continuing to keep details about additional cast members under wraps. With production progressing and the release date approaching, fans are expecting more character reveals in the months ahead as Marvel builds anticipation for one of the MCU’s biggest crossover events.