Billy Barratt joins HBO’s Harry Potter as Tom Riddle, with new Dobby and Ginny Weasley cast for Season 2

HBO has expanded the cast of its upcoming Harry Potter series, with Billy Barratt, Lenny Rush, and Bonnie Hill joining Season 2 as Tom Riddle, Dobby, and Ginny Weasley, respectively. The first season is also set to introduce a new generation of Hogwarts students to audiences this Christmas.

HBO casts Tom Riddle and Dobby for Season 2

The three actors will appear in the second season, which is set to adapt Harry Potter and the Chamber of Secrets - the second book in JK Rowling's seven-part series. Production is already moving ahead at Leavesden Studios in the UK, with HBO having renewed the series before its first episode even premiered.

Rush will play Dobby the house-elf who attempts to prevent Harry from returning to Hogwarts. This ends up forming one of the earliest mysteries of Chamber of Secrets. The character eventually becomes closely associated with Harry, particularly after the young wizard treats him with a kindness that Dobby rarely experienced.

In the original films, Dobby was brought to life through visual effects and voiced by Toby Jones. HBO has not publicly detailed how Rush's performance will be incorporated into the television adaptation.

Hill, meanwhile, is set to take over Gracie Cochrane's Ginny Weasley in Season 2. Cochrane's family announced earlier this year that she had decided to leave the series after the first season because of "unforeseen circumstances". HBO said it supported the decision and thanked her for her work.

Ginny has a relatively small presence in the first book, but her importance grows considerably in Chamber of Secrets. She becomes directly connected to the central mystery after receiving Tom Riddle's diary, which ultimately leads Harry towards the Chamber itself.

That makes Barratt's casting particularly significant. He will portray the young Tom Riddle, the Hogwarts student whose memory survives inside the enchanted diary and eventually reveals his connection to Lord Voldemort. Barratt joins a role previously played by Christian Coulson in the 2002 film adaptation.

The casting news arrives while HBO is still preparing to launch the story that started everything.

About Harry Potter Season 1

Season 1, officially titled Harry Potter and the Philosopher's Stone, follows Harry's discovery that he is a wizard, his arrival at Hogwarts and the friendships he forms with Ron Weasley and Hermione Granger. The first book also establishes the wider magical world, including the Hogwarts houses, Quidditch, the Forbidden Forest and the mystery surrounding the Philosopher's Stone.

Dominic McLaughlin leads the series as Harry, with Arabella Stanton as Hermione and Alastair Stout as Ron. John Lithgow plays Albus Dumbledore, Janet McTeer is Minerva McGonagall, Paapa Essiedu plays Severus Snape and Nick Frost takes on Rubeus Hagrid.

HBO has also given viewers a substantially fuller look at that first season. A new teaser released this week shows McLaughlin's Harry entering the wizarding world, with glimpses of the Hogwarts Express, the Sorting ceremony, Quidditch and the castle itself. It also points towards elements that were present in Rowling's first book but had less room in the original film adaptation.

The official Harry Potter site has described the series as a new television adaptation of the books, with each season expected to focus on a different instalment. The latest trailer therefore serves as more than a first look at a familiar story. It establishes the tone, performances and version of Hogwarts that will carry the franchise into its next television era.

The first season is scheduled to premiere on 25 December, 2026. Season 2 does not yet have a confirmed premiere date, but its early development means HBO is already laying the groundwork for Harry's second year at Hogwarts.

And with Dobby, Ginny and Tom Riddle now cast, some of the most important pieces of Chamber of Secrets are beginning to fall into place.