Jeffrey Wright stars as the Watcher, who narrates the series, alongside numerous MCU film actors reprising their roles. Development of the season began by July 2022, with Chauncey replacing previous head writer A. C. Bradley by December 2023. Andrews returned from previous seasons to direct.
The third season is expected to be released on the streaming service Disney+.
Work had begun on a third season of What If...? by July 2022.[4] At that time, head writerA. C. Bradley revealed that the second season of the series was her final project at Marvel Studios,[5][1] with series' story editor Matthew Chauncey taking over as head writer for the season.[1] Series' director Bryan Andrews returns for the third season.[6][7]: 4:28, 50:08–50:12 The season features a Red Guardian-centered episode written by Bradley that originally was intended for the second season, but was later moved to the third.[1] Bradley wrote the episode in 2020.[7]: 52:38–52:44
Writing
Executive producer Brad Winderbaum described the season as being the culmination of a trilogy, completing an "emotional experience" with the Watcher whose humanity is explored more than in previous seasons.[8][9] He added that the season would have the first hints at "crossover potential" between the series and Marvel Studios' other animated projects.[10] Some of the unused episode concepts that were created for the first and second season were used for the third.[11][12] Andrews said the third season's episode concepts were "wackier" than those used for the first two seasons,[11] and further explore different genres.[13] One episode features a Gundam-style Captain America mech,[14] and Andrews was excited to go "full, hardcore, mega genre" with the episode. Another episode revisits characters from the first season.[13]
Ideas that were considered for the season but not used include trying to involve the band Kiss in four different episodes, one of which would have been a galactic Battle of the Bands concept with Kiss serving as the judges, and a samurai episode that Andrews descibed as "hardcore and just brutal and awesome" with elements of Romeo and Juliet.[13]
The first footage from the season was released in December 2023, as part of the second season's "The Watcher's Nine Days of What If...?" Advent calendar-style website,[17] while images from the episodes were released the following month.[14]
Release
The third season will debut on Disney+.[4] In January 2024, Andrews stated he believed there had been the possibility of the season releasing at the end of 2024, but called that deadline "tight" and noted how Marvel Studios and Disney were continually shifting releases around.[6] That May, Winderbaum said work was nearly completed on the season and it was likely to be the studio's next animated project to be released.[8]