Lithgow confirmed his own casting in February and will join McTeer, Frost, Paapa Essiedu, Paul Whitehouse, and more in the franchise’s first TV adaptation.

Harry Potter series announces John Lithgow as Dumbledore, Janet McTeer as  McGonagall, Nick Frost as Hagrid, and more

Emmy and Tony-winning actor John Lithgow is officially confirmed to play Albus Dumbledore in HBO’s upcoming small-screen adaptation of the Harry Potter book series, stepping into the role played by both Richard Harris and Michael Gambon in the films. Lithgow announced his casting back in February, but he now has costars.

John Lithgow attends the 30th Annual Screen Actors Guild Awards at Shrine Auditorium and Expo Hall on February 24, 2024 in Los Angeles, California., Michael Gambon as Albus Dumbledore in Harry Potter and the Order of the Phoenix

John Lithgow in 2024, and Michael Gambon as Dumbledore in ‘Harry Potter and the Order of the Phoenix’.Axelle/Bauer-Griffin/FilmMagic; Murray Close/Warner Bros

Ozark star Janet McTeer tackles Minerva McGonagall, the role Maggie Smith made famous; I May Destroy You actor Paapa Essiedu takes on Severus Snape, Alan Rickman’s beloved anti-hero from the films; and rounding out the cast of series regulars, Nick Frost steps into the giant shoes of Rubeus Hagrid, the kindly Hogwarts groundskeeper who had been played by Robbie Coltrane. Smith died in 2024, Rickman in 2016, and Coltrane in 2022.

Several other coveted and widely speculated-over roles — including the titular role, of course, as well as Voldemort, Ron Weasley, and Hermione Granger — still remain unannounced. But the network did name two more actors in recurring roles: British stage actor Luke Thallon as Quirinus Quirrell (portrayed by Ian Hart in Harry Potter and the Sorcerer’s Stone) and veteran Welsh comedic actor Paul Whitehouse as Argus Filch (David Bradley across the Potter films).

Jason Isaacs wants Meryl Streep on ‘Harry Potter’ TV show as Lucius Malfoy
Jason Isaacs attends the "Honey Bunch" premiere; Harry Potter and the Order of the Phoenix (2007) Jason Isaacs as Lucius Malfoy

Janet McTeer attends the photocall for "Kaos" on August 28, 2024 in London, England ; Maggie Smith as Professor Minerva McGonagall in 'Harry Potter and the Deathly Hallows: Part 2' (2011).

Janet McTeer in 2024 and Maggie Smith in ‘Harry Potter and the Deathly Hallows: Part 2’.Kate Green/Getty ; ©2011 Warner Bros.

“We’re delighted to have such extraordinary talent onboard,” showrunner and executive producer Francesca Gardiner and director and executive producer Mark Mylod said in a statement. “We can’t wait to see them bring these beloved characters to new life.”

Harry Potter TV series was first announced in April 2023. While Warner Bros. Discovery noted that the author of the children’s book series out of which the massive, multimedia franchise sprang — the controversial J.K. Rowling — would executive produce, her involvement in the series would be limited.

Nick Frost attends the Premiere of "Get Away" on January 7, 2025 in London, England ; Robbie Coltrane as Hagrid in 'Harry Potter and the Chamber of Secrets' (2002).

Nick Frost in 2025 and Robbie Coltrane in ‘Harry Potter and the Chamber of Secrets’.Alan Chapman/Dave Benett/WireImage ; ©Warner Brothers/courtesy Everett Collection

HBO and Max CEO Casey Bloys clarified last November that Rowling remained “fairly involved” despite her virulent anti-transgender views, noting that he expected Rowling to “have opinions on casting.” But the views that have led franchise star Daniel Radcliffe and others to speak out against her haven’t “affected the casting or hiring of writers or production staff or anything, so we haven’t felt any impact from that,” according to Bloys.

A casting call for actors to play Harry, Ron, and Hermione was launched last September, requesting children between the ages of 9 and 11 who are residents of the U.K. or Ireland.

John Lithgow, Janet McTeer, and Nick Frost Harry Potter series casting

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Many have weighed in on who else they’d like to see in the series, including White Lotus star Jason Isaacs, who nominated Meryl Streep to replace him in the role of Lucius Malfoy, whom he played in six Potter films.

Chris Columbus, who directed the first two films in the franchise, said it would be “amazing” to see Oppenheimer star Cillian Murphy as the all-powerful Lord Voldemort, who was portrayed by a number of actors across the Potter films, most notably Ralph Fiennes.