The next chapter of the wizarding world is already underway — but one of its most infamous characters remains conspicuously absent from the official cast list.
HBO’s television reboot of the Harry Potter franchise has revealed most of its key players. Fans, however, believe they may have quietly uncovered another addition through an unexpected clue on social media.
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HBO’s ‘Harry Potter’ Reboot Begins Taking Shape
First announced in 2023, HBO’s adaptation of Harry Potter and the Philosopher’s Stone is currently filming its first season. The series will follow Harry’s arrival at Hogwarts, where he discovers the wizarding world, befriends Ron Weasley and Hermione Granger, and uncovers a mystery surrounding the school.
Warner Bros. Discovery confirmed the show’s central trio earlier this year. Dominic McLaughlin will portray Harry Potter, joined by Alastair Stout as Ron Weasley and Arabella Stanton as Hermione Granger.
The actors were selected following an open casting call that reportedly attracted more than 30,000 applicants.
Several prominent adult roles have also been filled. John Lithgow will play Albus Dumbledore, with Janet McTeer as Minerva McGonagall and Paapa Essiedu as Severus Snape.
Nick Frost will appear as Rubeus Hagrid, while Paul Whitehouse has been cast as Argus Filch.
Additional casting announcements include Luke Thallon as Professor Quirrell, Katherine Parkinson as Molly Weasley, and Johnny Flynn as Lucius Malfoy.
One character whose casting remains unknown is Lord Voldemort, originally portrayed by Ralph Fiennes in the original film series.
Rumors have circulated for months about who might take on the role. At various points, fans have speculated about Cillian Murphy, Paul Bettany, Tilda Swinton, and Tom Hiddleston.
HBO executives have urged viewers not to read too much into casting chatter. Casey Bloys, chairman and CEO of HBO and Max content, told Variety that fans should “take everything you read with a grain of salt.”
Social Media Activity Fuels Tom Riddle Theory
Despite the lack of official confirmation, fans believe they may have spotted a clue pointing to the actor who could portray Tom Riddle.
The theory emerged after several young cast members from the series began following British actor Owen Cooper on Instagram.
Some eagle-eyed fans have noticed that multiple young members of the Harry Potter cast, including Dominic McLaughlin, have suddenly followed British actor Owen Cooper on Instagram.
👀 This could be huge! Dominic McLaughlin (Harry Potter) has just followed Owen Cooper on Instagram. and he only follows 50 people!⚡
Cooper is widely considered a fan-favourite choice to play Tom Riddle in the HBO #HarryPotter series.
Could this be more than just a coincidence?🎬
👀 This could be huge! Dominic McLaughlin (Harry Potter) has just followed Owen Cooper on Instagram. and he only follows 50 people!⚡
Cooper is widely considered a fan-favourite choice to play Tom Riddle in the HBO #HarryPotter series.
Could this be more than just a… pic.twitter.com/694VgrCNmm— Harry Potter World Report (@HPNews_Germany) April 4, 2026
Cooper is best known for his performance as teenage murder suspect Jamie Miller in the Netflix series Adolescence. He also recently portrayed a younger version of Heathcliff in Wuthering Heights (2026).
In addition to McLaughlin, Arabella Stanton — who plays Hermione Granger — and Lox Pratt, cast as Draco Malfoy, now follow the actor.
At 16 years old, Cooper would fall within the age range typically associated with Tom Riddle during his Hogwarts years.
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What Could We Expect From Owen Cooper as Tom Riddle?
The character first appears in Harry Potter and the Chamber of Secrets, when Harry encounters a preserved teenage version of Riddle through a magical diary.
That memory manipulates Ginny Weasley — played in the reboot by Gracie Cochrane — and ultimately reveals that Riddle is the younger incarnation of Lord Voldemort.
The diary version of Riddle reopens the Chamber of Secrets and releases the basilisk beneath Hogwarts.
Tom Riddle’s history becomes even more significant later in the series. In Harry Potter and the Half-Blood Prince, Harry views memories of Riddle’s youth and early adulthood, gradually uncovering how the gifted student became the Dark Lord.
The storyline also introduces Horcruxes — fragments of Voldemort’s soul created through murder — which become central to the final books.
Several actors portrayed Riddle across the original film franchise. Christian Coulson appeared as the teenage version in Harry Potter and the Chamber of Secrets (2002).
Later flashbacks in Harry Potter and the Half-Blood Prince (2009) featured younger versions played by Frank Dillane and Hero Fiennes Tiffin.
In the novels, Tom Riddle is described as strikingly handsome and highly intelligent, traits that allow him to charm teachers and classmates while secretly pursuing dark magic.
The films hinted at this charisma but largely focused on his transformation into Voldemort.
Several moments exploring his early life were removed from the film adaptation of Harry Potter and the Half-Blood Prince (2009).
The movie omitted scenes showing Riddle’s childhood at Wool’s Orphanage, his ability to control other children, and his later work at Borgin and Burkes.
Another missing sequence involved the murder of Hepzibah Smith, which enabled him to obtain Hufflepuff’s Cup and Slytherin’s locket — both later turned into Horcruxes.
Cooper’s recent performances suggest why fans have latched onto the theory. His role in Adolescence required a calm, unsettling intensity — a mix of charm and menace that mirrors how Tom Riddle is described in the books: quietly manipulative and far more dangerous than he initially appears.
HBO has not addressed the speculation surrounding Cooper.
Reports suggest the studio plans to keep the actor portraying Voldemort secret for as long as possible — potentially delaying any reveal until the character first appears on screen. For now, the rumored casting remains unconfirmed.
