Apart from McLaughlin, Warwick Davis, who is known for his role as Professor Flitwick in the Harry Potterfilm series, will reprise his role for HBO’s Harry Potter. Elijah Oshin will portray Dean Thomas, Finn Stephens will essay Vincent Crabbe, and William Nash will play Gregory Goyle. Hogwarts professors who are cast are Sirine Saba as Professor Pomona Sprout, Richard Durden as Professor Cuthbert Binns, and Brid Brennan as Madam Poppy Pomfrey. Leigh Gill will portray Griphook in the series.

Arabella Stanton stars as Hermione Granger, and Alastair Stout as Ron Weasley. The rest of the cast includes John Lithgow, Janet McTeer, Nick Frost, Paapa Essiedu, Bertie Carvel, Anton Lesser, Paul Whitehouse, Johnny Flynn, and Bel Powley, amongst others.

Filming is currently underway for the series, which is written by Francesca Gardiner, with Mark Mylod serving as a director. Gardiner and Mylod serve as executive producers with author JK Rowling, Neil Blair, David Heyman, and Ruth Kenley-Letts. Bronte Film, Heyday Films, and Warner Bros Television are backing the series, which is set to premiere in 2027.