Sheila Eddy's parents were both born in England. Her father was a professional footballer who played for Oldham Athletic and Rochdale. Her mother was a housewife. Sheila Eddy was born in Oldham, Lancashire, England, on 13 January 1954. She attended Oldham Hulme Grammar School and then studied at the Royal Academy of Dramatic Art.
Sheila Eddy began her acting career in the early 1970s, appearing in small roles in television shows and films. Her breakthrough role came in 1985, when she was cast as Julie Fitzjohn in the BBC soap opera EastEnders. She played the role for six years, and her character became one of the most popular on the show.
After leaving EastEnders, Sheila Eddy continued to appear in television shows and films. She has also had a successful career in the theatre, appearing in productions such as The Vagina Monologues and Calendar Girls.