[Landen.jpg|right|250px|thumb|Dinsdale Landen portraying Dr Judson possessed by the evil Fenric, from the [[Doctor Who] serial The Curse of Fenric]]
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 when he starred in the TV series Mickey Dunne and The Spies during the 1960s. He also had a parallel career as a stage actor, including as Richard Dazzle in the RSC's 1970 production of London Assurance.