The Mewtwo Mega Evolutions (Mega Mewtwo X and Mega Mewtwo Y) are scheduled to be available during Pokémon GO Fest 2026: Global on July 11–12, 2026.

Quick Scoop: Key Date

  • Mega Mewtwo X and Mega Mewtwo Y will make their Pokémon GO debut during GO Fest 2026: Global.
  • The global GO Fest 2026 event runs on July 11 and July 12, 2026 , and that’s when all players can access the event content.
  • Mega Energy for Mewtwo and the ability to Mega Evolve it into its two forms will be tied to special raid content during that same GO Fest window.

So if you’re asking “what date in Pokémon GO Fest 2026 is Mewtwo Mega Evolution,” the answer is: both July 11 and July 12, 2026 , as part of GO Fest Global’s raid lineup.

Official Event Context

Several official and news-style sources line up on the same basic info:

  • GO Fest 2026: Global is confirmed for July 11–12, 2026 , celebrating the game’s 10-year anniversary.
  • Announcements explicitly state that Mega Mewtwo X and Mega Mewtwo Y will debut during this Global GO Fest 2026.
  • Coverage notes that the global event is free for all players , so anyone logging in that weekend can participate in the Mega Mewtwo raids and related Special Research without a paid ticket.

In other words, the Mewtwo Mega Evolution feature is not limited to a single narrow time slot; it’s a highlight mechanic of the whole global weekend.

In-Person vs Global Dates (For Extra Clarity)

Some guides and community posts also mention in‑person GO Fest 2026 dates where Mega Mewtwo first appears:

  • Tokyo Waterfront City, Japan: May 29 – June 1, 2026 (Mega Mewtwo X debut at in‑person GO Fest).
  • Grant Park, Chicago, USA: June 5 – June 7, 2026.
  • Fælledparken, Copenhagen, Denmark: June 12 – June 14, 2026.

However, your question is specifically about Pokémon GO Fest 2026 Global , and for that:

  • Global GO Fest with Mega Mewtwo X/Y is on July 11–12, 2026.
  • This is the window when worldwide players can farm Mega Mewtwo raids, collect Mega Energy, and unlock the Mega Evolution for Mewtwo on their accounts.

Mini FAQ & Multi‑Viewpoints

1. Is it one day or two days?

  • View 1 – “Single debut moment”: Some fans expected a one‑day debut, like a special “Mewtwo Day” during GO Fest.
  • View 2 – “Weekend feature”: Official info makes it clear Mega Mewtwo is a core weekend feature , available across both July 11 and 12.

Evidence strongly supports View 2: Mega Mewtwo X/Y are tied to GO Fest Global raid rotation over the whole weekend , not just a brief window.

2. Can you miss Mewtwo Mega if you only play one of the days?

  • You’ll have more chances if you play both days, but sources suggest Mega Mewtwo raids are part of the standard GO Fest raid schedule, not a one‑hour event.
  • That means you should see raid opportunities on either July 11 or July 12, though the exact hourly schedule may vary.

3. How does Mewtwo Mega Evolution work during GO Fest?

  • Mewtwo can Mega Evolve into Mega Mewtwo X or Mega Mewtwo Y using specific forms of Mega Energy, obtainable from GO Fest Super Mega Raids.
  • Once you’ve collected enough of that Mega Energy and have a Mewtwo, you can trigger the Mega Evolution in‑game from the Raid/Mega interface.

Short Answer (TL;DR)

The Mewtwo Mega Evolutions (Mega Mewtwo X and Mega Mewtwo Y) are available during Pokémon GO Fest 2026: Global on July 11 and July 12, 2026 , and they are a featured part of the raid content for the whole weekend.

Information gathered from public forums or data available on the internet and portrayed here.