Blair guest starred in two episodes of '; appearing in 1975, along with Anthony Valentine, in ' and in 1976, along with Freddie Jones, in "Journey to Where". In 1976, Blair played Emma Antrobus in the ITV drama series "The Crezz". She played a principal role (Sally) in the BBC's alternate history TV serial "An Englishman's Castle", first broadcast in 1978. One of her best known TV appearances was as Flora Beniform in "The History Man" (1981) alongside Anthony Sher. Blair played Claire Carlsen, Francis Urquhart's Parliamentary Private Secretary, in "The Final Cut" (1995). In 2003, she played opposite John Nettles in an episode of Midsomer Murders as a psychological profiler. She played Nanny Langton in "The Star of Jacob", "Father Brown" (S5:E1, 2016).