Bertie Carvel, who has played roles including Tony Blair in The Crown, will be the new Cornelius Fudge.
And a string of newcomers have been cast as Hogwarts students - Leo Earley as Seamus Finnigan, Alessia Leoni as Parvati Patil, and Sienna Moosah as Lavender Brown.
They join a crop of other names on the show's growing cast list including the child actors who will play Harry, Hermione and Ron, as well as John Lithgow as Dumbledore, Nick Frost as Hagrid and Paapa Essiedu as Severus Snape.
The TV version of JK Rowling's books, being made by HBO, is expected to reach screens in late 2026 or early 2027.