Jones graduated from the drama schoolRADA and performed in numerous plays including Pride and Prejudice and The Women on the West End stage. Her first television role came in 1961 when she appeared in one episode of Coronation Street as a policewoman. Jones's first major television role was in BBC's 1967 adaptation of The Forsyte Saga. Jones played the maid, Smither, a small but recurring part. Later, she appeared twice in Nearest and Dearest. Prior to playing Blanche Hunt in Coronation Street her best-known role was as Polly Barraclough in Sam with Mark McManus. In 1967, several years after her first Coronation Street role she had another guest role on the opposite side of the law, as a shoplifter. In 1974, she made her first appearance as Blanche Hunt, the mother of Deirdre. The part had originally been played by Patricia Cutts, who committed suicide after appearing in only two episodes. Jones, who had previously auditioned for the role, accepted an offer to take over the part at short notice as storylines had already been written for Blanche. Jones remained a regular cast member until 1976. She re-appeared in the show briefly when Blanche's grandchild Tracy was born in 1977, when Deirdre's marriage to Ray Langton collapsed in 1978 and when Deirdre married Ken Barlow in 1981. Throughout the 1980s, Jones was a regular face on British television, appearing in several series. These included The Barchester Chronicles, The Beiderbecke Tapes, In Sickness and in Health, Sharon and Elsie, We'll Think Of Something, The Nesbitts Are Coming, Bulman and Lovely Couple, alongside Pauline Quirke. After guest appearances in shows such as Dalziel and Pascoe, Goodnight Sweetheart, Heartbeat and Peak Practice in the 1990s, Jones reprised the role of Blanche Hunt in Coronation Street in 1996. She became a regular cast member again in 1999. Blanche's trademark withering one-liners and no-nonsense attitude made her a firm favourite of fans of the long-running show. In 2005 and 2008, Jones won the British Soap Award for Best Comedy Performance. Jones stated that she didn't think of her character as funny and that she couldn't play her properly if she did.
On 18 April 2008, Jones fell, injuring her knee and shoulder at the Manchester hotel in which she stayed while filming Coronation Street. She took two weeks off work on Coronation Street to recover from the accident. She was written out of the series again when she fell ill in October 2009.