
John Leeson, the British actor whose distinctive voice brought the robotic dog K9 to life in Doctor Who, has died at 83. His son, filmmaker Guy Ducker, announced that Leeson died peacefully on November 1, 2026, after a period of illness. No specific cause of death has been announced.

A Voice Fans Will Always Recognize
Leeson first voiced K9 in the 1977 Doctor Who story “The Invisible Enemy,” opposite Tom Baker as the Fourth Doctor. The character was intended for a single adventure, but audiences took to the clever robotic dog—and Leeson’s performance helped make him a lasting part of the series.
K9’s crisp delivery, dry humor and polite confidence gave the mechanical companion a personality all his own. Leeson returned to the role in K-9 and Company, The Sarah Jane Adventures and other Doctor Who productions, as well as in audio dramas. When K9 reappeared in the 2006 series, Leeson once again supplied the character’s voice.
Former Doctor Who showrunner Russell T Davies praised Leeson’s performance, remembering the humor and personality he brought to K9.
A Career Beyond Doctor Who
Born John Ducker in 1943, Leeson trained at the Royal Academy of Dramatic Art and built a career across television, theatre, radio and voice work. His screen credits included Dad’s Army, Blake’s 7, The Bill and Doctors. He was also the original performer of Bungle in the children’s series Rainbow.
Though many viewers knew him first as the voice of K9, Leeson’s work reached far beyond one role. He continued performing in audio productions, returning to a character that had become part of television history.
Remembering John Leeson
John Leeson gave K9 more than a voice: he gave the character warmth, wit and an unmistakable presence. His performance helped turn a small robotic dog into one of Doctor Who’s most enduring companions.
Fans will remember Leeson for the joy and personality he brought to K9, and for a long career that touched generations of television viewers.