Avengers: Doomsday spoilers are coming sooner than you think — Marvel fans, mute your keywords now

Every so often, the stars (and the studio accountants) align to give us one of those box office pile-ups you just can’t look away from. 18 December 2026 is now officially such a date. Instead of studios ducking out of each other’s way, like they usually do with major tentpoles, Avengers: Doomsday and Dune: Part Three are both barreling headlong into a release day collision. It’s so over-the-top, it’s earned its own hybrid hashtag: Dunesday. Yes, really.

Both Avengers: Doomsday and Dune: Part Three will open December 18, 2026, sparking calls of the biggest box office clash ever.

Two Blockbusters, One Day

Let’s be clear, having these two juggernauts on the same day is borderline mad. Usually, one studio blinks (hello, Barbenheimer effect), but it appears neither Marvel nor Warner Bros. wants to budge.

Avengers: Doomsday isn’t just any Marvel film either. It’s the first Avengers flick that’s NOT kicking off the summer blockbuster season. Instead, they’re gambling on a winter blowout, and early signs look solid—pre-sales are apparently breaking records already. Not bad for a day that’s already a crown jewel for Hollywood: December 18 has seen the releases of James Cameron’s Avatar (2009) and Star Wars: The Force Awakens (2015), both historic earners in their own right.

International Rollout Gets Complicated (As Usual)

Here’s where it gets really fun for fans: depending where you live, you’ll be seeing Doomsday before the Americans, for once. The UK will get Avengers: Doomsday on 16 December 2026, a full two days ahead of the North American crowd. India’s getting in even earlier—17 December—and doing multi-language screenings (expect English, Hindi, Tamil, and Telugu from day one).

India is set for an early launch, with Robert Downey Jr. and Chris Evans popping up in a Diwali video confirming the December 17th release over there.

This sort of thing isn't new for Marvel, mind: both the original Avengers and Age of Ultron opened overseas earlier than in the States, sometimes by a week. They played around with dates again when they wanted to hide Endgame and Infinity War's twists, bringing forward their North American launches. Still, even then, the UK snuck in early by a day or two. So it’s not a wild head start, but there’s just enough time for fans (and trolls) to start chucking spoilers online the moment the credits roll.

What We Know About Doomsday

There’s plenty of speculation flying, especially with directors Joe and Anthony Russo suggesting that characters not even mentioned in the official cast lists might turn up. That's exactly the kind of rumour-mongering Marvel fans eat up, balanced by the usual warnings to go full blackout mode on social media unless you fancy spoilers.

Robert Downey Jr. has made noises about Doomsday shifting the MCU from classic Marvel banter to something a bit more Infinity War—starting light, going properly dark, ending with a sledgehammer moment. Marvel's calling this one the penultimate chapter of their much-hyped Phase Six saga, winding everything up next year in 2027 with Avengers: Secret Wars.

• Avengers: Doomsday debuts UK: 16 Dec 2026; India: 17 Dec 2026; North America: 18 Dec 2026
• Dune: Part Three opens 18 Dec 2026 (global)
• Marvel's last record-breaking hit: Spider-Man: Brand New Day, earlier in 2026
• Doomsday is part two of a two-part MCU finale; wraps up in 2027