Born in Chorley, he trained at RADA and made his professional debut at Liverpool's Everyman Theatre in 1965. His theatre work included a six-year stint at the Royal Shakespeare Company and it was in the Shakepearean role of Friar Laurence that he made one of his first television appearances in a production of Romeo and Juliet in 1965. He has since appeared in many series, including Sam, Crossroads, The Old Curiosity Shop and Play for Today. He currently concentrates on bringing the work of Roald Dahl to life for children, within which work he has played the role of the BFG in 1666 performances.
Pedley should have continued for several weeks playing Harry Scott but after taping his first two episodes the 1979 ITV strike broke out and he was unavailable to take up the role again when the dispute came to an end in October. The character of Jack Walsh was hurriedly created and Donald McKillop contracted to play him.
As Pedley remembers: "I often wonder how my life might have turned out had it not been for that strike, because I was scheduled to appear for many more episodes as a possible love interest with Thelma's Mavis - just think, Derek would have been Harry!!...The ITV strike happened and I wasn't able to go back to the programme afterwards because I'd taken other work, and they wrote me out - telling Mavis that Harry's work had called him elsewhere. Pity, but then again I may not have had the opportunity to play all those different roles over the years."