Voice Actor John Leeson, Who Voiced K9 in Doctor Who, Dies at 83

John Leeson, the actor best known for voicing the robot dog K9 in the television series Doctor Who, has died at the age of 83.

His son, Guy Ducker, announced the news on social media on Monday. Ducker stated that his father died after a summer of illness and that his passing was peaceful. He expressed gratitude to the fan community for the love shown to his father over many years.

Leeson was born John Ducker in 1943. He received his training at the Rada school of acting. He built a career in theater and television, appearing in productions such as Dad’s Army, Sorry!, Crown Court, and Longitude. His television credits also include The Bill, Vanity Fair, Doctors, and Blake’s 7. He served as a continuity announcer for Channel 4.

The character of K9 was created by Bob Baker and Dave Martin. The robotic dog first appeared in the 1977 Doctor Who episode The Invisible Enemy, starring Tom Baker. Production teams initially planned for the character to appear in only that one story. They decided to keep the character on the show because they believed younger viewers would connect with him. Leeson voiced the character until 1981. David Brierly took over the role for a period before Leeson returned.

Leeson reprised the role for the 20th anniversary special of Doctor Who. He also appeared in the spin-off series K-9 and Company. That show featured Elisabeth Sladen, who played the companion Sarah Jane Smith. Leeson and Sladen worked together again in the 2006 Doctor Who episode School Reunion, which starred David Tennant. The pair also starred in the CBBC series Sarah Jane Adventures. That show ran from 2007 until Sladen’s death in 2011.

Russell T Davies, a former showrunner for Doctor Who, posted a tribute on Instagram following the news of Leeson’s death. Davies said there was no doubt the production team would ask Leeson to voice the robot when it returned. He described the character as a posh, uppity, and haughty dog that was also wry and innocent. Davies noted that the pitch was perfect for children to imitate. He called Leeson a true gentleman and a great loss.

Keith Barnfather, a producer of behind-the-scenes documentaries about Doctor Who, worked with Leeson starting in the 1980s. Barnfather described the actor as kind, considerate, professional, charming, talented, and unassuming. Lisa Bowerman, who has worked across the Doctor Who franchise, remembered Leeson as a lovely man and excellent company. She described his voice as truly iconic.

Leeson worked as a hospital porter after leaving school before he auditioned for Rada. He described his career in two parts. He said the first half was primarily as a stage actor. He said the television half arose by accident. He recalled a stint playing Bungle on the children’s show Rainbow. He said the costume work left him feeling ill inside the suit. He also recalled being upset about an army haircut he received for Dad’s Army, noting that he was then placed in a balaclava and helmet, making the hair invisible.

Leeson remained active in the role of K9 into his later years. He provided voices for Big Finish audio dramas last year. He previously recalled a conversation with BBC producers after his first episode. They told him not to expect anything after the first episode was filmed. He noted that he was still attached to Doctor Who in 2025.