TMDb/Avengers: Doomsday Movie Avengers: Doomsday vs. Dune 3 clash on Dec 18, 2026. IMAX exclusivity for Dune leaves Marvel without U.S. premium screens. The "Dunesday" showdown is set. March 19, 2026 AceShowbiz - Last May, Marvel Studios made a significant scheduling change for Avengers: Doomsday, shifting its release from the franchise's traditional early May slot to a December 18, 2026 premiere. This move placed the film in direct competition with Denis Villeneuve's Dune: Part Three. Both Marvel and Disney appear committed to this clash, with stars Robert Downey Jr.