John Lithgow cast as Dumbledore in HBO's Harry Potter

HBO is accelerating development of its highly anticipated Harry Potter TV series, securing a major casting breakthrough with veteran actor John Lithgow reportedly set to portray Professor Dumbledore.

The network's prolonged search for their new Dumbledore appears concluded, as Lithgow confirmed his acceptance of the iconic role during a ScreenRant interview, describing it as a career-defining opportunity for his later years.

"This came completely unexpectedly," Lithgow revealed. "I received the call while attending Sundance Film Festival for another project. It wasn't an easy decision since this role will likely shape my professional legacy in these final chapters."

The acclaimed actor added: "I'm genuinely excited. Seeing such talented creators revisit the Wizarding World makes this special. I'll be nearing 87 by the time we wrap, but I've committed to the journey."

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While marking the first confirmed casting, Lithgow's involvement remains unofficial pending announcements from HBO and Warner Bros. Discovery.

The ambitious adaptation plans to comprehensively retell J.K. Rowling's original book series with entirely new portrayals of beloved characters including Harry, Hermione, Ron and other Hogwarts residents. Rowling will executive produce alongside Neil Blair and Ruth Kenley-Letts.

Despite Lithgow's public confirmation, the absence of a complete cast suggests production timelines remain distant. The celebrated actor brings significant prestige to the project, having earned fame through sitcom 3rd Rock from the Sun and an Emmy-winning Winston Churchill portrayal in Netflix's The Crown.