Chris Columbus, the original director of the Harry Potter films, has praised the upcoming HBO reboot series as a "spectacular idea" due to its potential to more faithfully adapt the beloved books. In an interview with People, Columbus highlighted the limitations he faced with the shorter runtimes of the films, specifically when directing "Harry Potter and the Sorcerer's Stone" and "Harry Potter and the Chamber of Secrets." He noted that the team endeavored to include as much content from the books as possible, yet the constraints of film length meant they could only cover so much.

"I think it's a spectacular idea because there’s a certain restriction when you’re making a film," Columbus explained. "Our film was two hours and 40 minutes, and the second one was almost as long. The fact that they have the leisure of [multiple] episodes for each book, I think that's fantastic. You can get all the stuff in the series that we didn't have an opportunity to do... All these great scenes that we just couldn't put in the films."

Announced in April 2023, the Harry Potter series promises to be a "faithful adaptation" of the novels, aiming to tell a more comprehensive and "in depth" story than what is possible in a two-hour film format. The project will be helmed by Succession producers Francesca Gardiner and Mark Mylod, with the latter having previously contributed to Game of Thrones.

HBO is currently in the process of casting the iconic roles of Harry, Hermione, and Ron. As for Dumbledore, original Sirius Black actor Gary Oldman humorously suggested he might be the right age to take on the role of Hogwarts' headmaster, reflecting on his debut in "The Prisoner of Azkaban" two decades ago.

Actor and playwright Mark Rylance is reportedly at the top of the casting wishlist for Dumbledore, maintaining the original films' preference for British actors. This choice aligns with the involvement of J.K. Rowling, the series' controversial original author, who is "fairly involved" in the casting process.

Filming for the Harry Potter TV series is set to commence in spring 2025, with HBO aiming for a release in 2026.