Marvel Studios Releases First Full Trailer for 'Avengers: Doomsday,' Featuring Robert Downey Jr.'s Return

With San Diego Comic-Con kicking off later this week, Marvel Studios has released the first official full trailer for Avengers: Doomsday, the penultimate film in the MCU’s Phase Six and the end of the so-called “Multiverse Saga.”

Marvel Studios originally planned to build its Phase Six Avengers arc (The Kang Dynasty) around Jonathan Majors’ Kang the Conqueror (and associated variants), introduced in Loki and Ant-Man and the Wasp: Quantumania. But then Majors was convicted of domestic violence, and Marvel fired the actor soon after. That meant the studio needed to retool its Phase Six plans, culminating in the announced return of the Russo brothers, who directed four of the Marvel Cinematic Universe’s most successful films, which brought in more than $6 billion at the global box office.

The Russo brothers decided to take a new direction, bringing the Secret Wars storyline to the big screen. It’s one of their favorites, but before they could take on Avengers: Secret Wars (slated for May 2027), the duo knew they first had to make Avengers: Doomsday, featuring the wildly popular comics villain Doctor Doom, with the return of Robert Downey Jr. to the MCU in that role.

The film takes place 14 months after the events of Thunderbolts*. Per the official logline: “Beloved heroes from three distinct universes will be set on a deadly collision course and face an existential threat unlike anything they’ve ever encountered.” Those universes are Earth-616 (the Avengers, Wakandans, and New Avengers), Earth-828 (Fantastic Four), and the “original” X-Men.

A few good superheroes

Cast-wise, we have Avengers favorites Thor (Chris Hemsworth), the new Captain America (Anthony Mackie), Bucky Barnes (Sebastian Stan), Ant-Man (Paul Rudd), Falcon (Danny Ramirez), and Loki (Tom Hiddleston). Then there’s the Wakandan contingent: Shuri as the new Black Panther (Letitia Wright), M’Baku (Winston Duke), and Namor (Tenoch Huerta Mejia), as well as Alex Livinalli as Namor’s ally, Attuma. And, of course, Robert Downey Jr. as Doctor Doom.

Then there’s the Thunderbolts* (aka New Avengers): John Walker/US Agent (Wyatt Russell), Yelena Belova (Florence Pugh), Bob/Sentry (Lewis Pullman), Red Guardian (David Harbour), and Ghost (Hannah John-Kamen). And the Fantastic Four: Reed Richards (Pedro Pascal), Sue Storm (Vanessa Kirby), Ben Grimm (Ebon Moss-Bachrach), and Johnny Storm (Joseph Quinn). We’ll also see Charles Xavier (Patrick Stewart), Beast (Kelsey Grammer), Magneto (Ian McKellen), Mystique (Rebecca Romijn), Nightcrawler (Alan Cumming), and Cyclops (James Marsden).

For good measure, Marvel threw in Gambit (Channing Tatum) and Xu Shang-Chi (Simu Liu). There will be plenty of cameos, like Steve Rogers (Chris Evans), revealed in one of four sneak teasers last year. We can also expect to see (at least briefly) Peggy Carter, Spider-Man (Tom Holland), Hawkeye (Jeremy Renner), Doctor Strange (Benedict Cumberbatch), Thor’s adopted daughter Love (India Rose Hemsworth), and Scott Lang’s daughter Cassie (Kathryn Newton).

So what’s in the trailer? A heck of a lot of cameos, mostly, as the superheroes from the three universes meet each other over an ominous voiceover by Thor warning of an unprecedented threat. “I’ve fought with many warriors in my time,” we hear Thor say. “They were far stronger than all of us put together. And they died. They died facing enemies and threats that scared me far less than this one. Everything that they sacrificed will be for nothing if we do not stand together. Put aside your petty squabbles and presume nothing except this. If you return, you will return as brothers and sisters. But mark my words, we’re going to need a miracle.”

OK, not exactly the St. Crispin’s Day speech, but the trailer ends with the return of Steve Rogers—and guess what, he’s still worthy of Thor’s hammer, Mjölnir. Could he be the miracle they need? Or is another miracle waiting in the wings?

Avengers: Doomsday hits theaters on December 18, 2026. Avengers: Secret Wars is currently slated for release on December 17, 2027, and will mark the conclusion of the MCU’s Phase Six.