HBO's Harry Potter might have just cast an Oscar winner for villain Voldemort

Excitement around HBO’s upcoming Harry Potter TV series has been quietly building for months, but it’s just spiked thanks to a possible case of accidental spoiler magic from the man who knows Voldemort better than anyone.

Ralph Fiennes, who played the Dark Lord across the original film franchise, appears to have let something slip while speaking on the red carpet, and fans think he may have revealed who’s been cast as the series’ new Voldemort. The name he dropped? Cillian Murphy.

Asked again who should step into his shoes for the reboot, Fiennes initially suggested the role had already been cast, before adding, “I think Cillian Murphy is very good. A very good choice.” What followed was a moment of visible uncertainty, as Fiennes began questioning whether the casting had actually been confirmed at all, glancing nervously towards his team as if realising he might have just unleashed a chunky spoiler.

The clip quickly made the rounds online, sending the Harry Potter fandom into full meltdown mode. Murphy has long been a popular fan-casting for Voldemort, thanks to his unsettling screen presence and recent run of heavyweight performances, from Peaky Blinders to his Oscar-winning turn in Oppenheimer.

That said, nothing is officially confirmed. In fact, Murphy has previously shut down rumours of his involvement altogether. Speaking on the Happy Sad Confused podcast last year, he insisted he knew nothing about the role, adding that he was only aware of the speculation because of his children. “I don’t know anything about that,” he said. “Ralph Fiennes is an acting legend, good luck to whoever’s gonna fill those shoes.”

The Oscar-winning actor is already on a busy schedule with the upcoming Peaky Blinder's film, The Immortal Man, and is also rumoured to be returning in the third 28 Years Later film.

Context matters here. HBO’s Harry Potter reboot is expected to run for a full decade, with each season adapting one of the seven novels. That means Voldemort, who doesn’t properly return until The Goblet of Fire, may not appear on screen for years yet, making the idea of a casting reveal now feel either wildly premature or genuinely accidental.

Casting is already underway, however with newcomers Dominic McLaughlin, Arabella Stanton and Alastair Stout have been announced as the new Harry, Hermione and Ron, while John Lithgow will play Dumbledore, Paapa Essiedu takes on Snape, Janet McTeer is McGonagall, and Nick Frost steps in as Hagrid. And, it was recently confirmed that music-legend Hans Zimmer officially set to write an original score for the series.

Whether Fiennes genuinely revealed a closely guarded secret or simply mistook long-running rumours for fact remains unclear. HBO has yet to comment, and Murphy remains officially unattached to the project. Something the Oscar-winning actor will need to consider, much like the rest of the cast, is the potential scrutiny he could face thanks to the series creator, J.K. Rowling's openly transphobic views.

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