John Leeson is a British actor who is known for voicing K-9 on the television series Doctor Who from 1977 to 1979, then from 1980 to 1981, and has returned for two single episode in the revived series. He also voiced K-9 in the show's spin-offs K-9 and Company, The Sarah Jane Adventures and K-9.
2025Doctor Who: Gallifrey as Unknown
2025The Doctor Who Escape Room: Team Third Doctor as K9 (voice)
2017The Doctors: The Tom Baker Years as Unknown
2015Longleat '83: The Lost Footage as Unknown
2013The Five(ish) Doctors Reboot as Self
2011Pointless Celebrities (1 Episode) as K-9 (voice)
2010Sarah Jane's Alien Files (6 Episodes) as K9
2009K-9 (26 Episodes) as K-9 (voice)
2008The K-9 Files as Unknown
2008Celebration: Doctor Who in 1983 as Unknown
2007A Matter of Time as Unknown
2007Parrot Fashion as Unknown
2007Getting Blood from the Stones as Unknown
2007The Sarah Jane Adventures (10 Episodes) as K9 (voice)
2007The Sarah Jane Adventures: Invasion of the Bane as K9
2005Doctor Who (2 Episodes) as K9 (voice)
2004A New Beginning as Unknown
2003Doctor Who @ 40 Weekend as Presenter - K9 (Voice)
2003Doctor Who: Shada as K9 (voice)
2001Longleat '83: The Greatest Show in the Galaxy as Himself - Host
2000K9 Unleashed as Unknown
1998Where on Earth Is Katy Manning? as Unknown
1995Bugs (1 Episode) as Harris
1995Downtime as Anthony the D.J.
1993Doctor Who: Dimensions in Time as K9 (voice)
1990Search Out Space as K9 (voice)
1988Doctor Who: Remembrance of the Daleks as Voices
1987Myth Runner as Himself
1986Whoops Apocalypse as TV Interviewer
1984Myth Makers 2: John Leeson as Unknown
1984'Allo 'Allo! (1 Episode) as Train's Cook
1983Doctor Who: The Five Doctors as K9 (voice)
1982The Barretts of Wimpole Street as Henry Barrett
1981K-9 and Company: A Girl's Best Friend as K-9 (voice)
1981K-9 and Company (1 Episode) as Unknown
1981Sorry! (42 Episodes) as Unknown
1981Doctor Who: Warriors' Gate as K9 (voice)
1980Doctor Who: State of Decay as K9 (voice)
1980Doctor Who: Full Circle as K9 (voice)
1980Doctor Who: Meglos as K9 (voice)
1980Doctor Who: The Leisure Hive as K9 (voice)
1979Tarka the Otter as Secretary of the Hunt
1979Minder (1 Episode) as Passport Officer
1979Doctor Who: The Armageddon Factor as K-9 (voice)
1979Doctor Who: The Power of Kroll as Dugeen
1978Doctor Who: The Androids of Tara as K-9 (Voice)
1978Doctor Who: The Stones of Blood as K-9 (voice)
1978Doctor Who: The Pirate Planet as K-9 (voice)
1978Doctor Who: The Ribos Operation as K-9 (voice)
1978Doctor Who: The Invasion of Time as K9 (voice)
1978Doctor Who: Underworld as K-9 Mk. I (voice)
1978Blake's 7 (1, 1 Episode) as Pasco, Toise
1977Doctor Who: The Sun Makers as K9 Mk. I (voice)
1977Doctor Who: The Invisible Enemy as K-9 Mk. I (voice) / Nucleus (voice)
1972Rainbow (105 Episodes) as Bungle
1970On the House (1 Episode) as Young Man
1963Doctor Who (80, 4 Episode) as K9 (voice), Dugeen