He graduated from the Royal Academy of Dramatic Art in 1961 and appeared in their production of The Doctor and The Devils by Dylan Thomas. Alderton first became familiar to television viewers in 1962, when he played Dr Moone in the ITV soap opera Emergency Ward 10. After an uncredited role in Cleopatra (1963), and appearing in British films such as The System (1964), Assignment K (1968), Duffy (1968) and Hannibal Brooks (1969), he played the lead in the comedy series Please Sir!, as hapless teacher Mr Hedges, which later resulted in him also playing the character in the 1971 feature film of the same name. He was cast by Richard Lester in the title role of a film version of Flashman but the project was abandoned.[3]
He made his first stage appearance with the repertory company of the Theatre Royal, York in August 1961, in Badger's Green by R.C. Sherriff. After a period in repertory, he made his first London appearance at the Mermaid, November 1965, as Harold Crompton in Spring and Port Wine, later transferring with the production to the Apollo. At the Aldwych. In March 1969, he played Eric Hoyden in the RSC's production of Dutch Uncle. At the Comedy Theatre, July 1969, he played Jimmy Cooper in The Night I Chased the Women with an Eel. At the Howff, in October 1973, he played Stanley in Punch and Judy Stories, and played the same part in Judies at the Comedy, January 1974. At the Shaw Theatre, London,in January 1975, he played Stanley in Pinter's The Birthday Party. At the Apollo, London in May 1976, he played four parts in Ayckbourn's Confusions.
Alderton married actress Jill Browne in 1964, but they divorced.[1] In 1969, he married actress Pauline Collins and they have three children, a daughter (Kate, who is also an actor[1]) and two sons.[1][4]
