Using his mournful appearance he was often portrayed as a world-weary police officers or butlers, and indeed it is for the part of Chief Inspector Claud Eustace Teal in the cult 1960s series The Saint, opposite Roger Moore, that he is most remembered. Dean played Teal for nearly the whole run of the series, except three episodes where other artistes were used. It was in an episode called ‘Starring The Saint’ which featured Dean in another role, that the producers saw the ideal actor for the part.
Dean proved the perfect foil for Roger Moore's Simon Templar, invariably one step behind and allegedly hoping for the day when he could stick something on the Saint. Dean's character however seemed to have a respect for Simon Templar. The role was reprised in all but name in Randall and Hopkirk (Deceased) (1968–69) in which he played Inspector Large, who had the same adversarial relationship with the private investigator ,Jeff Randall.
Dean also appeared in quite a few other ITC series, including Jason King and The Persuaders!, he appeared as 'Jarvis' the butler in 3 episodes of the long-running LWT sitcom Doctor at Large and featured in three episodes of The Avengers. In 1964 he played estate agent Alfred Wormold in the long-running soap opera Coronation Street, selling No. 13 Coronation Street to Stan Ogden and his wife Hilda.
Ivor Dean was also a impressive Long John Silver in a Franco-German television version of Treasure Island, entitled Die Schatzinsel/L'ile au Tresor (1966). He contributed to a follow-up script with Saint producer Robert S. Baker, but it never materialised before his death, however Baker continued to develop the project and it was finally made as the 10 part serial Return to Treasure Island in 1986, it was scripted by John Goldsmith and the part of Long John Silver was played by Brian Blessed.
His other film appearances include Theatre of Death and the 'Pride' segment of The Magnificent Seven Deadly Sins.
Ivor Dean was married to the actress Patricia Hamilton. He died in Truro, Cornwall. In August 1974.