Two of 2026’s biggest movies are officially heading into theaters on the same day.

Marvel Studios’ Avengers: Doomsday and Warner Bros. Pictures and Legendary’s Dune: Part Three are both scheduled for release on December 18, 2026, creating a blockbuster double feature fans have already nicknamed “Dunesday.”

The comparison follows the success of “Barbenheimer,” the fan-created event that formed when Barbie and Oppenheimer opened together in July 2023. Moviegoers turned the unusual pairing into a major theatrical celebration by watching both films during the same weekend.

Avengers: Doomsday will bring together heroes from the Avengers, Fantastic Four and X-Men franchises as they face an existential threat led by Victor von Doom. Robert Downey Jr. returns to the Marvel Cinematic Universe as Doctor Doom, while Anthony and Joe Russo direct the crossover.

Marvel Studios officially lists Avengers: Doomsday for an exclusive theatrical release on December 18, 2026.

Dune: Part Three will conclude Denis Villeneuve’s Dune trilogy and is based on Frank Herbert’s novel Dune Messiah. Timothée Chalamet and Zendaya return alongside Jason Momoa, Florence Pugh, Rebecca Ferguson, Anya Taylor-Joy, Robert Pattinson and Javier Bardem.

Legendary Pictures also lists Dune: Part Three for December 18, 2026, with Warner Bros. handling distribution.

The shared date could lead to one of the most competitive opening weekends in recent memory. Avengers: Doomsday will arrive with the global reach of the Marvel Cinematic Universe, while Dune: Part Three is expected to receive a major premium-format release, including IMAX presentations.

Neither studio has announced plans to move its film away from the date. Unless one schedule changes, audiences will be able to choose between Doctor Doom’s multiversal war and Paul Atreides’ return to Arrakis—or watch both as part of “Dunesday.”

Legendary Pictures also lists Dune: Part Three for a theatrical release on December 18, 2026: https://www.legendary.com/film/dune-part-three/