HBO’s "Harry Potter" Series Close to Find Its Snape & McGonagall

HBO is closing in on two more main cast members for its high-profile TV adaptation of the hugely popular “Harry Potter” book series.

Oscar-and Emmy-nominated actress Janet McTeer is in talks to play Professor Minerva McGonagall.

Additionally, Emmy nominee Paapa Essiedu, one of the first actors identified for the series, is closing his deal to portray Professor Severus Snape.

They are poised to join John Lithgow, who will be playing Professor Albus Dumbledore.

“We appreciate that such a high-profile series will draw a lot of rumor and speculation,” HBO said in a statement. “As we make our way through pre-production, we will only confirm details as we finalize deals.”

The series, designed to run over a decade, comes from writer-showrunner Francesca Gardiner and director/executive producer Mark Mylod.

Casey Bloys, chairman and CEO of HBO and Max Content, at the time of the original announcement, called the series a “faithful adaptation” of J.K. Rowling’s novels that will “dive deep into each of the iconic books.”

Speaking at a Max event in London last December, Gardiner revealed the series will stick to the “canonical” ages of Snape, who will be only 31, as well as the Dursleys, who will be much younger than they were in the movies.

That explains the choice of thirtysomething Essiedu for the role of Snape, the antagonist-turned-hero played in the Harry Potter movies by the late Alan Rickman.

Severus Snape is a Professor of Potions at the Hogwarts School of Witchcraft and Wizardry who eventually becomes Headmaster.

Meanwhile, McTeer is just a couple of years younger than the late Maggie Smith was when she was cast as Deputy Headmistress Minerva McGonagall in the film franchise two and a half decades ago.

The Transfiguration professor at Hogwarts, McGonagall also is the nurturing head of Gryffindor House and the Deputy Headmistress under Headmaster Albus Dumbledore (Lithgow).

In the Fantastic Beasts prequel films, the role was played by Fiona Glascott.

With the HBO series, the Harry Potter franchise continues to build a more inclusive and racially diverse universe, an effort that started with the casting of Noma Dumezweni as Hermione in the long-running stage play Harry Potter and the Cursed Child.

It is something another popular fantasy franchise, The Lord of the Rings, also embarked on when transitioning to the small screen with the Amazon series.

The Harry Potter TV series, which will be filmed at Warner Bros Studios Leavesden where the movies were shot, is slated to debut on HBO in late 2026 or early 2027.

Some 32,000 kids sent audition tapes for the lead roles of Harry, Hermione and Ron, with the final casting choices yet to be revealed.