The new HBO Harry Potter series has not even reached Hogwarts yet, but its second season is already revealing some seriously major pieces of the wizarding world. HBO has announced three important additions for Season 2: Lenny Rush as Dobby, Bonnie Hill as Ginny Weasley and Billy Barratt as the young Tom Riddle.

The timing is notable. Season 1, adapting Harry Potter and the Philosopher’s Stone, is still months away from its December 25, 2026 premiere on HBO. Yet the production is already assembling the characters who will drive Harry Potter and the Chamber of Secrets — including one fan-favorite magical creature, a future key member of the Weasley family and the boy whose story eventually leads to Lord Voldemort.

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HBO ‘Harry Potter’ Season 2 Cast Adds Dobby, Ginny Weasley and Tom Riddle

For longtime Potter fans in the UK and USA, these three casting announcements instantly make the second season feel much more real.

Dobby is coming back. Ginny Weasley is getting a new actor from Season 2 onward. And Tom Riddle, one of the most important figures in the mythology behind Voldemort, now has his HBO-era performer.

Here is what has officially been announced so far:

Character	Actor	Season	Role in the Story
Dobby	Lenny Rush	Season 2	Harry’s mysterious house-elf ally
Ginny Weasley	Bonnie Hill	Season 2 onward	Ron’s younger sister and key Chamber of Secrets character
Tom Riddle	Billy Barratt	Season 2	Young version of the future dark wizard
Harry Potter	Dominic McLaughlin	Season 1 onward	Main protagonist
Hermione Granger	Arabella Stanton	Season 1 onward	Harry’s closest friend
Ron Weasley	Alastair Stout	Season 1 onward	Harry’s closest friend

The three new additions also give audiences an early look at just how much darker and more complicated the HBO adaptation could become once it moves beyond the first book.

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Lenny Rush Cast as Dobby for ‘Harry Potter and the Chamber of Secrets’

Perhaps the biggest immediate talking point is Dobby.

Lenny Rush has been cast as the beloved house-elf for Season 2. Rush is already known for appearances in Doctor Who, Enola Holmes 2 and Am I Being Unreasonable?, and he has also won a BAFTA for his acting.

Dobby becomes central to Harry’s story in Harry Potter and the Chamber of Secrets. The house-elf repeatedly tries to stop Harry from returning to Hogwarts because he knows danger is waiting for him there.

That warning becomes one of the earliest clues that something seriously wrong is about to happen at the school.

Dobby was previously brought to life through visual effects in the original Harry Potter film franchise, with Toby Jones providing the character’s voice. Now, HBO’s adaptation will introduce its own version of the iconic magical character as the television story reaches the events of the second book.

For fans who remember Dobby as one of the original franchise’s most recognizable magical creatures, his arrival is one of the clearest signs that Season 2 is moving into familiar territory while giving the story a new visual and dramatic identity.

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Bonnie Hill Takes Over Ginny Weasley Role From Season 2

The Ginny Weasley casting comes with a major change of its own.

Bonnie Hill has been cast as Ginny for Season 2, replacing Gracie Cochrane, who was previously announced for the role in the first season.

Cochrane will still appear as Ginny in Season 1, which adapts Harry Potter and the Philosopher’s Stone. However, she will not continue with the series beyond the first season. Her departure has been attributed to “unforeseen circumstances.”

That means viewers will effectively see two different performers play Ginny as the HBO adaptation moves from its first book into its second.

HBO previously issued a statement supporting Cochrane and her family following the change:

“We support Gracie Cochrane and her family’s decision not to return for the next season of HBO’s Harry Potter series, and we are grateful for her work on season one of the show. We wish Gracie and her family the best.”

Ginny is Ron Weasley’s younger sister, but her importance grows considerably as the wider story develops.

In The Chamber of Secrets, she is a first-year Hogwarts student whose story becomes deeply connected to the mystery surrounding the attacks at the school. Her storyline is therefore not simply another addition to the Weasley family — it becomes directly tied to the central mystery of Season 2.

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Billy Barratt Will Play Young Tom Riddle in HBO’s Harry Potter Reboot

Then there is Tom Riddle.

Billy Barratt has been cast as the young Tom Riddle, giving HBO its first announced actor for the character who will eventually become Lord Voldemort.

Riddle plays a crucial role in Harry Potter and the Chamber of Secrets. The story introduces audiences to a younger version of the future dark wizard through the mysterious diary discovered by Harry.

The diary, Riddle’s history and the secrets surrounding Hogwarts gradually connect as the mystery unfolds, making the character one of the most important pieces of the second story.

Barratt is an award-winning British actor whose credits include Apple TV+’s Invasion and the film Kraven the Hunter. He also became the youngest recipient of an International Emmy for acting when he won at the age of 13 for his performance in Responsible Child.

His casting could give the HBO series another opportunity that the original movies had less room to explore: spending additional time with Riddle’s younger years and his connection to Hogwarts.

The original films used multiple actors to portray Tom Riddle at different ages. Christian Coulson played the teenage Riddle in Harry Potter and the Chamber of Secrets, while other performers portrayed different stages of his life.

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Why Season 2 of HBO’s Harry Potter Series Could Feel Very Different

Season 2 will adapt Rowling’s second novel, Harry Potter and the Chamber of Secrets, continuing Harry, Hermione Granger and Ron Weasley’s second year at Hogwarts.

That story introduces several major elements that were not present in the first book, including Dobby, the Chamber of Secrets, the basilisk and Tom Riddle’s diary.

And this is where the HBO format could become particularly interesting.

The television adaptation is being developed as a long-form version of Rowling’s seven-book saga, giving each book substantially more room to develop its characters and storylines than the original film series had.

Francesca Gardiner serves as writer and executive producer, while Mark Mylod is an executive producer and is directing multiple episodes.

The series is being produced by HBO in association with Brontë Film and TV and Warner Bros. Television.

J.K. Rowling is among the executive producers, alongside Neil Blair and Ruth Kenley-Letts of Brontë Film and TV and David Heyman of Heyday Films.

Warner Bros. Discovery has described the television project as a faithful adaptation of the books.

That approach is particularly relevant for The Chamber of Secrets, where seemingly smaller character moments eventually become essential to the central mystery.

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HBO Harry Potter Cast Already Includes Major New Stars

The three Season 2 additions join a young central cast led by Dominic McLaughlin as Harry Potter, Arabella Stanton as Hermione Granger and Alastair Stout as Ron Weasley.

The adult cast is equally notable.

John Lithgow plays Albus Dumbledore, Janet McTeer takes on Minerva McGonagall, Paapa Essiedu portrays Severus Snape and Nick Frost plays Rubeus Hagrid.

The ensemble also includes Rory Wilmot as Neville Longbottom and Lox Pratt as Draco Malfoy, alongside numerous other actors portraying students, teachers and members of the wider wizarding world.

There has also already been another significant Season 2 development: Kit Harington has taken on the role of Gilderoy Lockhart.

Harington replaced Nicholas Hoult, who departed the project.

Lockhart’s presence will add another very different personality to the second season, placing the charming but questionable celebrity wizard alongside the increasingly dangerous mystery surrounding Hogwarts.

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When Does HBO’s Harry Potter Season 2 Come Out?

For anyone already wondering when they can watch the new Dobby, Ginny and Tom Riddle, there is one important detail to keep straight: HBO has not announced a Season 2 premiere date.

The confirmed immediate release is Season 1.

HBO’s new Harry Potter series will premiere on December 25, 2026, adapting Harry Potter and the Philosopher’s Stone.

Season 2 will move into Harry Potter and the Chamber of Secrets, but HBO has not provided a specific release date or official release window.

So while the growing Season 2 cast may fuel speculation about production and scheduling, its premiere date should not be treated as confirmed until HBO makes an official announcement.

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Dobby, Ginny and Tom Riddle Set Up a Much Bigger Harry Potter Story

There is a bigger reason these three casting choices matter.

Dobby represents one of the franchise’s most recognizable magical creatures and becomes an important ally to Harry. Ginny expands the Weasley storyline while becoming directly connected to the mystery at Hogwarts. Tom Riddle, meanwhile, provides a crucial link to one of the saga’s central villains.

Together, they point directly toward the darker mystery at the heart of The Chamber of Secrets.

The HBO series also has something the original movies did not have to the same extent: more television runtime to explore the source material. That could allow these characters and their storylines more room to develop, although HBO has not yet revealed exactly how the second season will structure those stories.

For now, the confirmed casting is clear.

Lenny Rush will play Dobby. Bonnie Hill will play Ginny Weasley beginning with Season 2. Billy Barratt will portray Tom Riddle.

Season 1 of HBO’s Harry Potter premieres on December 25, 2026, while the release date for Season 2 remains officially unannounced.

Disclaimer

This article has been prepared following thorough research based on information confirmed by HBO/Warner Bros. Discovery and corroborated by reputable entertainment reporting available as of September 5, 2026, including reporting from Variety, the Warner Bros. Discovery Pressroom, the Los Angeles Times and Entertainment Weekly. Details about Season 2 that have not been officially announced, including its premiere date and specific plot or production details, should be treated as unconfirmed.

Sources

• Variety — Harry Potter HBO Series Casts Dobby, Ginny Weasley and Tom Riddle
• Warner Bros. Discovery Pressroom — HBO Original Harry Potter Television Series Cast Announcement
• Warner Bros. Discovery Pressroom
• Los Angeles Times — Harry Potter TV Series Cast Reveal
• Entertainment Weekly — Harry Potter Season 2 Casts Dobby, Tom Riddle and Ginny Weasley

Featured Image Credit: Warner Bros. / HBO