Born in Hoxton, East London, he looked set for a technical trade when his grandmother, the music hall artist Lilly Randall, suggested at the age of 14 that he attend drama lessons to help with his dyslexia. Soon afterwards Prunella Scales saw him reciting Shakespeare in the Petticoat Lane Market and advised him to take drama lessons. He did so with Joan Littlewood and became a professional actor at the age of 18. After many lean years, he appeared in the series Law and Order in 1978 and his career on television blossomed from then on with appearances in Minder, Shoestring and Hammer House of Horror in quick succession. In 1983 he appeared in Woodentop, the pilot for The Bill and two years later achieved stardom when he was one of the original cast of the BBC’s latest but most successful answer to Coronation Street, EastEnders, which made its debut in February 1985 and in which he played market trader Pete Beale.
In December 1990 Dean and fellow EastEnders cast member Michael Melia travelled to Manchester and appeared briefly in the thirtieth anniversary spectacular Happy Birthday Coronation Street where they reminisced about their brief time on the northern soap. Three years later, Dean had a major fall-out with the producers of EastEnders and was sacked. Fellow cast member (and also previously a guest star on Coronation Street) June Brown quit in protest with him but was persuaded to return to the show after four years. Although he has made limited television appearances since then, Dean has acted on the stage in pantomime and in the play Entertaining Mr Sloane.