Chadbon's film work includes The Alf Garnett Saga (1972), The Beast Must Die (1974), Juggernaut (1974), Tess (1979), Coming Out of the Ice (1982), Dance with a Stranger (1985), Shooting Fish (1997), and Casino Royale (2006).
He played Duggan in the Doctor Who serial City of Death (1979) and returned to Doctor Who as Merdeen in the 1986 serial The Trial of a Time Lord. Chadbon has also been an occasional guest star in Big Finish audio productions. Most notably, he played the recurring character of Will in the second series of the Sarah Jane Smith audio adventures. He also had a featured guest role in No More Lies, during Paul McGann's 2007 broadcast season on BBC Radio 7.
Chadbon starred in all 10 episodes of Crown Prosecutor (1995), playing Lenny Monk, and he had substantial recurring roles in Chancer, The Liver Birds, Where the Heart Is, Wire in the Blood, and the 23rd series of Casualty (as Professor Henry Williams).