In his early life Martin worked as a professional gambler, motor racer, at a meat market and as a debt collector.

[1] Martin started his entertainment career as a stuntman on programmes including Doctor Who, but after breaking his collar bone filming the drama Elizabeth R (1971) he switched to acting.

In 1978, Martin co-starred with Peter Dean in the BBC television series Law & Order, playing Detective Inspector Fred Pyall.

He has also made guest appearances in many television programmes, including returning to Doctor Who to play policeman David Mitchell in Image of the Fendahl (1977), The Sweeney episode "Messenger of the Gods" as the villain Spooner, Upstairs, Downstairs, The Bill and Only Fools and Horses.

He was written out of the show on Thursday, 7 January 2016, in part one of two episodes, in which his character suffered a cardiac arrest.

In January 2012, Martin appeared as one of the first five couples in the third series of Celebrity Coach Trip partnering fellow actor John Altman.