Theatre star Luke Thallon will take on a leading role in the new Harry Potter TV show on HBO alongside John Lithgow, Paapa Essiedu and Paul Whitehouse.

Thallon, from Surrey, was recently praised for starring as Hamlet in the Royal Shakespeare Company’s 2025 production – before being picked for the Harry Potter casting.

And while Thallon has a number of theatre roles under his belt, he is less known to TV viewers.

Who is Luke Thallon?

The 29-year-old made his professional debut in Mike Bartlett’s production of Albion at the Almeida in 2017. This was also during his final year at the Guildhall School of Music & Drama.

He won the Clarence Derwent Award for his performance in Tom Stoppard’s Leopoldstadt (2020), and was a nominee for the Evening Standard Emerging Talent Award. 

Talking about playing Hamlet for the RSC, he told Deadline: “If you want to honour the part and honour the tradition of previous actors and the quality of their work, you feel a great pressure and a great obligation to spend as much time as you can.”

He also spoke about how he’d like to do something on screen in the near future.

Alongside his theatre credits, Thallon has also starred in radio shows including A Room With A View and The Age of Anxiety.

Harry Potter stars - where are they now?

Who is Luke Thallon playing in the new HBO Harry Potter series?

Thallon will play Quirinus Quirrell, taking over from Ian Hart, who played the character in Harry Potter and the Philosopher’s Stone.

Quirinus is Harry, Ron and Hermione's first Defence Against the Dark Arts teacher when they begin Hogwarts in year one.

Harry Potter HBO TV series cast

The most anticipated announcement was for the Harry Potter HBO Hagrid casting which went to Nick Frost.

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Other cast members for the Harry Potter TV series, announced by HBO, are:

  • John Lithgow as Dumbledore

  • Paul Whitehouse as Argus Filch

  • Paapa Essiedu as Severus Snape

  • Janet McTeer as Minerva McGonagall

The series is expected to debut on Max and HBO and Warner Bros Discovery streaming services in 2026.