Former co-star Julie Goodyear described her as "a true icon and legend and a very dear friend". ITV said Driver died peacefully in hospital on Saturday.
Driver joined the ITV show as barmaid Betty Turpin, later Williams, in 1969.
She had already been in the entertainment business for more than 40 years, touring the UK as a singer by the age of 12. Driver was appointed an MBE (Member of the Order of the British Empire) in 1999.
Driver had originally auditioned for the role of Hilda Ogden in 1964 but was later persuaded to come out of retirement to audition for the role of Betty. She appeared in more than 2,800 episodes.
In January 2011 she told the BBC she would never retire. "I just love working and I will never retire - ever - they'll have to shoot me to get rid of me," she said. "I just love people, you see, and I love the cast."
Driver had been in hospital for six weeks. "She will be sadly missed by everyone who knew her," an ITV spokesman said.