'Harry Potter' 20th anniversary: first look as Harry, Ron and Hermione reunite at Hogwarts

Daniel Radcliffe, Emma Watson and Rupert Grint come together for the one-off HBO Max special, set to air on New Year's Day

Daniel Radcliffe, Emma Watson and Rupert Grint come together for the one-off HBO Max special. Photo: HBO

HBO has released the first image from its coming Harry Potter reunion special, which will mark 20 years since the release of the first film in the ever-popular franchise.

The still from Harry Potter 20th Anniversary: Return to Hogwarts shows actors Daniel Radcliffe, Emma Watson and Rupert Grint, who played Harry, Ron and Hermione in all eight films, in conversation inside Hogwarts.

The stars will share their memories from the decade-long franchise, which saw them thrust into the spotlight as children, making them among some of the most recognisable stars in the world.

They will be joined for the special by the likes of Robbie Coltrane (Hagrid), Matthew Lewis (Neville Longbottom), Mark Williams (Arthur Weasley), Ralph Fiennes (Lord Voldemort), Helena Bonham Carter (Bellatrix Lestrange) and Gary Oldman (Sirius Black).

The special is set to air on HBO Max on January 1.

Based on the books by JK Rowling, the Harry Potter films are among the most successful movie franchises ever made. Rowling, however, is notably absent from the special. While the author will feature in archive footage that will be shown, it's unclear whether her controversial comments about transgender issues in 2020 were the reason for her absence.

The image comes in the same week that HBO released the first trailer for the special, which featured some familiar faces, as well as the signature Harry Potter music and the famous platform 9¾, the invisible station at London’s Kings Cross, where the Hogwarts Express is waiting to depart.

The special also marks 10 years since the release of the final film, Harry Potter and The Deathly Hallows Pt 2.

The TV special is one of several 20th-anniversary events planned by Warner Bros, including a TV quiz contest for Potter fans hosted by Dame Helen Mirren, which will include cameo appearances by some of the cast as well as celebrity fans including comedians Pete Davidson and Jay Leno.

Scroll through the gallery below to see what the stars of 'Harry Potter' look like now: