British actor John Leeson, best known for providing the voice of K9, the iconic robotic dog in the long-running science fiction television series Doctor Who, has died at the age of 83.

His death was announced by his son, Guy Ducker, in a Facebook post on Sunday, November 1, 2026. He disclosed that his father died peacefully at 3:03 p.m. following a period of illness during the summer.

Leeson, born John Ducker in Leicester, England, on March 16, 1943, trained at the prestigious Royal Academy of Dramatic Art (RADA) before building a successful career across television, theatre and radio.

He became widely recognised in 1977 when he first voiced K9, the robotic dog introduced in the Doctor Who serial The Invisible Enemy, starring Tom Baker as the Fourth Doctor.

Although K9 was initially intended to appear in just one story, the character quickly became popular with viewers and was retained as one of the Doctor’s companions.

Leeson continued voicing K9 until 1981 and later reprised the role in several productions, including the 1983 anniversary special The Five Doctors, the 2006 revival of Doctor Who and the spin-off series The Sarah Jane Adventures.

He also continued lending his voice to K9 in audio dramas, with some of his most recent work appearing in 2025.

Beyond Doctor Who, Leeson had an extensive acting career, featuring in popular British television programmes including Dad’s Army, Blake’s 7, The Bill, Minder and ‘Allo ‘Allo!.

He also played Bungle the Bear in the popular children’s television programme Rainbow, further establishing himself as a familiar face and voice in British entertainment.

Former Doctor Who showrunner Russell T Davies paid tribute to the actor, describing him as a true gentleman and praising his distinctive performance as K9.

Davies said it was impossible to imagine anyone else providing the voice when the robotic character returned to the programme in 2006.

Leeson’s son also expressed appreciation to the Doctor Who fan community for the affection and support shown to his father throughout his decades-long career.

He is survived by his wife, Judy Griffiths, and son, Guy Ducker.

His portrayal of K9 remains one of the most memorable contributions to the Doctor Who franchise, having entertained generations of television audiences.