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.

Did you know John Lithgow has New Jersey ties? Here's who is playing what character on HBO's 'Harry Potter' series and when you can watch the show.

Max's Harry Potter TV series has officially cast four series regulars and two recurring roles, including four actors Deadline previously revealed: John Lithgow as Albus Dumbledore, Janet McTeer as Minerva McGonagall,