Dinsdale James Landen (4 September 1932 — 29 December 2003) was a British actor known mainly for his television appearances.
Landen was born at Margate. He made his television debut in 1959 as Pip in an adaptation of Great Expectations and made his film debut in 1960, with a walk-on part in The League of Gentlemen. He first became well known during the 1960s when he starred in the TV series Mickey Dunne and The Mask of Janus, which was renamed The Spies in later series. He also had a parallel career as a stage actor, including as Richard Dazzle in the RSC's 1970 production of London Assurance.
On radio, he appeared in the 1976 BBC Radio 4 adaptation of Jim Eldridge's novel Down Payment on Death as Art Gordo. He also portrayed Rupert Purvis in the 1982 production of Tom Stoppard's play The Dog It Was That Died and played the urbane Ambassador McKenzie in four series of Flying the Flag.
In 1977 Landen starred in his own situation comedy, Devenish, playing a Basil Fawlty type character in a Reggie Perrin-type situation; designing board games. In 1980 he starred as Barty in the television series Pig In The Middle with Liza Goddard.
In 1987 he played the lead in a BBC TV production of What the Butler Saw, playing Dr Prentice in a production also featuring Prunella Scales, Timothy West and Bryan Pringle.
In 1989 he made a guest appearance in Doctor Who, playing Dr. Judson, a wheelchair-using genius, in the serial The Curse of Fenric.
Dinsdale Landen died at his home in South Creake, Norfolk on 29 December 2003 after becoming ill with pneumonia. He had been diagnosed with oral cancer several years before his death, but was in remission at the time. He was married to the actress Jennifer Daniel.