Richard's agent, Kevin Francis, said she died in a London clinic with husband John Burns by her side.
Born Wendy Emerton, Richard was raised above the pub her parents ran in central London. She left school at 15 and worked at the Fortnum and Mason department store before studying drama.
She had parts in several of the cheap-and-cheerful "Carry On" film comedies, and in TV shows including "Up Pompeii!" and "The Likely Lads" before becoming famous as Miss Brahms, a staff member of the fictional Grace Brothers department store in 1970s sitcom "Are You Being Served?"
Richard was known to millions around the world as put-upon matriarch Pauline Fowler in "EastEnders," a long-running soap set in a close-knit east London neighbourhood.
Richard appeared in the show's first episode in 1985 and stayed for 21 years, depicting Pauline through trials that included her daughter's teen pregnancy, her son's HIV diagnosis and her husband's breakdown, imprisonment and death.
Richard was diagnosed with cancer in the mid-1990s and again in 2002, and learned last year that the disease had returned and spread.
She is survived by Burns, her long-term partner and fourth husband, whom she married in October.
