HBO's Harry Potter series has filled three roles that define Harry's second year at Hogwarts. Lenny Rush will play Dobby, Billy Barratt will play Tom Riddle, and Bonnie Hill will take over as Ginny Weasley in Season 2.
The casting news lands before the first season has even premiered. Harry Potter and the Philosopher's Stone arrives at Christmas 2026, while the already-renewed second season will adapt The Chamber of Secrets. HBO has not announced a Season 2 release date.
Who will play Dobby and Tom Riddle?
Lenny Rush is taking on Dobby, the house-elf who appears at Privet Drive with a warning for Harry: returning to Hogwarts is a terrible idea. Rush has appeared in Am I Being Unreasonable?, Dodger, Enola Holmes 2, and A Woman of Substance.
The announcement says Rush will play Dobby, but HBO has not explained how the performance will be created. The character was computer-generated in the films and voiced by Toby Jones, so details about voice work, on-set reference, or performance capture are still unknown.
Billy Barratt will play the teenage Tom Riddle. Barratt has credits in Bring Her Back, Kraven the Hunter, Blinded by the Light, and the Apple TV series Invasion. Christian Coulson played the same version of Riddle in the 2002 Chamber of Secrets film.
Riddle is much more than a name from Hogwarts history. His preserved teenage self lives inside an old diary, drawing Harry into the central mystery and revealing an important piece of Voldemort's past.
Bonnie Hill is the new Ginny Weasley
Bonnie Hill will begin playing Ginny Weasley in Season 2. Gracie Cochrane remains in the role for the first season, but Cochrane and her family announced in May that she would step away afterward because of unforeseen circumstances. HBO supported the decision and thanked her for her work.
Hill's previous credits include The Six Triple Eight, Film Club, and Girl Troop versus Aliens. She is joining just as Ginny moves from a brief introduction into one of the story's most important roles.
In The Chamber of Secrets, Ginny starts her first year at Hogwarts and becomes attached to Riddle's diary. The object seems private and comforting at first, but its influence pulls her into the danger spreading through the school.
Why all three roles are central to Season 2
Dobby, Ginny, and Riddle initially look like three separate pieces of the story. Dobby brings the warning, Ginny carries the mystery, and Riddle offers answers that are never as helpful as they seem. Their stories eventually meet inside the Chamber of Secrets.
That connection gives this casting announcement more weight than a normal group of supporting additions. HBO has now chosen the performer behind the season's emotional center, the face at the heart of its mystery, and one of the franchise's most recognizable magical creatures.
The second book also expands Hogwarts beyond the discoveries of Harry's first year. Students are attacked, the school faces the possibility of closing, and Harry begins hearing a voice no one else can hear. The new cast members will have to carry much of that tension around the returning trio.
What we know about Harry Potter Season 2
Season 2 received an early renewal and is expected to begin filming in fall 2026. A premiere date, episode count, and full cast list have not been announced.
Before then, HBO still has to launch Harry Potter and the Philosopher's Stone. The eight-episode first season introduces Dominic McLaughlin as Harry, Arabella Stanton as Hermione, and Alastair Stout as Ron. A recent Harry Potter trailer offered the clearest look yet at their first year inside Hogwarts.
Dobby, Riddle, and the new Ginny will not be part of that main first-year mystery. Their arrival belongs to the next chapter, and HBO has now put faces to the three characters who make Harry's return to Hogwarts so dangerous.
