
HBO's Harry Potter reboot series started announcing cast members as production prepares to begin this summer.
Warner Bros. held an open casting call to find its Harry, Ron, and Hermione, along with the rest of its youngsters. The studio received auditions from thousands of children and is expected to select its Golden Trio in the coming months.
HBO's Harry Potter Reboot Cast So Far (Confirmed & Rumored)
John Lithgow - Albus Dumbledore (Confirmed)

After rumored castings from Mark Rylance to Mark Strong, the six-time Emmy-winning actor John Lithgow will officially play Professor Albus Dumbledore.
Dumbledore is the Headmaster of Hogwarts and arguably the greatest wizard in magical history who leads the fight against Voldemort and his dark forces.
The acclaimed star confirmed his casting in an interview with Screen Rant, revealing it was "not an easy decision" to sign on as the seven-season HBO show will "define [him] for the last chapter of [his] life:"
"Well, it came as a total surprise to me. I just got the phone call up at the Sundance Film Festival for yet another film, and it was not an easy decision because it's going to define me for the last chapter of my life, I'm afraid. But I'm very excited. Some wonderful people are turning their attention back to 'Harry Potter.' That's why it's been such a hard decision. I'll be about 87 years old at the wrap party, but I've said yes."
Lithgow's casting was a great surprise since the actor is American, and the Harry Potter franchise usually sticks to British talent. Meanwhile, Lithgow will also turn 80 this year, meaning he will be around 87 when the seventh and final season wraps.
The actor has racked up many credits in his over five-decade-long acting career, not least of which was in Dexter, The Crown, Shrek, and 3rd Rock from the Sun.
Paapa Essiedu - Severus Snape (Confirmed)

Paapa Essiedu was recently reported by Deadline to be nearing a deal to play Professor Severus Snape in the HBO reboot. As Essiedu is a Black actor, his casting marks a race swap from Snape's usual white portrayal.
Snape is Hogwarts' Potions Master and the Head of Slytherin who has a history as a Death Eater and a powerful hatred towards Harry Potter.
But fans of the franchise will be well aware that Snape has a history with Harry's mother, Lily, and his motivations are not as villainous as they initially seem.
Essiedu gave his Emmy-nominated breakout performance in the BBC's I May Destroy You, while he also appeared in Murder on the Orient Express.
Janet McTeer - Minerva McGonagall (Confirmed)

As part of the same Deadline report, the outlet claimed Janet McTeer is in negotiations to play Professor Minerva McGonagall, following rumors that Sharon Horgan and Rachel Weisz may have also been in the mix.
As the Head of Gryffindor, Transfiguration professor, and Deputy Headmistress at Hogwarts, McGonagall is known for being strict while also fair and caring.
63-year-old McTeer has credits in Ozark, Jessica Jones, and Kaos, while she will soon appear in Mission: Impossible - The Final Reckoning.
Brett Goldstein - Rubeus Hagrid (Rumored)

In an article that reported various casting rumors for the Harry Potter reboot, Deadline noted Brett Goldstein as one actor who might play Rubeus Hagrid.
The half-giant Hagrid is the Hogwarts groundskeeper who eventually becomes a professor teaching Care of Magical Creatures in The Prisoner of Azkaban. He serves as a friendly and caring figure to the Golden Trio across the seven books.
Goldstein does not have the typical larger build that would be expected for the half-giant Hagrid. But as HBO is the studio that transformed Colin Farrell into The Penguin, it should be achievable through makeup and prosthetics.
Most will recognize Goldstein from Ted Lasso (Season 4 of which recently got an official update), but he also appeared in Thor: Love and Thunder and Shrinking.
Cillian Murphy - Quirinus Quirrell (Rumored)

Scooper DanielRPK took to his Patreon (via CBR) to claim that Cillian Murphy is being "eyed" by HBO to play Professor Quirnus Quirrell in the Harry Potter reboot.
Fans know Quirrell as the Defence Against the Dark Arts professor in The Sorcerer's Stone, with Voldemort's face hiding on the back of his head. As Quirrell doesn't survive the first book, Murphy would likely only appear in Season 1.
The Oscar-winning actor previously appeared in Peaky Blinders, Oppenheimer, 28 Days Later, and Batman Begins.
Phoebe Waller-Bridge - Petunia Dursley (Rumored)

Another Patreon rumor shared by DanielRPK (via Comic Book Movie) said that Phoebe Waller-Bridge has been offered the role of Aunt Petunia Dursley.
If she accepted, Waller-Bridge would play one-half of the Dursleys, Harry's horrible aunt and uncle who raised him after his parents' deaths.
The London-born star is best known for Indiana Jones and the Dial of Destiny, Fleabag, Killing Eve, and Crashing.
Cillian Murphy - Voldemort (Rumored)

Some rumors have also been flying about, saying Cillian Murphy might play Lord Voldemort in HBO's Harry Potter reboot, taking over from Ralph Fiennes.
Fiennes gave his full blessing for Murphy to play Voldemort in an interview with Bravo's Watch What Happens Live (via Variety), praising him as a "fantastic actor" who he would "be all in favor" of taking over his movie role:
"Cillian is a fantastic actor. That’s a wonderful suggestion. I would be all in favor of Cillian. Yeah."
While these claims have been all over social media since the series was announced, they appear to be completely unsubstantiated and untrue.
Voldemort does not truly appear in person until The Goblet of Fire, the fourth book, which will not be adapted for several years. As such, any rumors regarding who will play the iconic villain for the foreseeable future are likely baseless.
Read about more one Stranger Things star rumored to play Voldemort.
The Harry Potter reboot series will premiere on HBO in 2027.