John Lithgow is stepping into the role of Dumbledore for HBO's 'Harry Potter,' but he did have his reservations.

The Emmy-winning actor, hot off a SAG Award for "Conclave," said playing the Hogwarts headmaster would "define me for the last chapter of my life."

John Lithgow confirmed in a new interview with ScreenRant that he will be playing Albus Dumbledore in HBO’s “Harry Potter” television series. Variety reported earlier this month that Lithgow was eyeing the role.

John Lithgow, the latest addition to the cast of HBO's Harry Potter remake, has commented on joining a series "full of great actors."

All the news on HBO's streaming 'Harry Potter' TV series, including cast, release date, how to watch, development and whether J.K. Rowling will be involved.

And there’s more! A new cast will fill the old roles made famous by the likes of Daniel Radcliffe, Rupert Grint, Emma Watson, and Co. There aren’t many details about the series available just yet, but here’s a quick breakdown of what we do know so far.

The cast of HBO's 'Harry Potter' is finally taking shape, as the six-time Emmy winner John Lithgow has confirmed his role as Hogwarts headmaster.

The other week, we learned that American actor John Lithgow would play Albus Dumbledore in HBO's upcoming Harry Potter TV show, the first major casting announcement to come out of this series. Now, Deadline has the scoop on a couple more actors circling major roles.

Recent reports have confirmed that John Lithgow will play Dumbledore in the new HBO Harry Potter series. Related: ‘Harry Potter’ Star Emma Watson Defends Her Label Of ‘Self-