The singer, who had a home in Estepona, southern Spain, died Saturday, according to Spanish police.
The cause was not immediately disclosed, said The Hollywood Reporter.
Black had a 50-year music and television career.
She was born Priscilla White in Liverpool, northwest England. The singer worked as a teenager in the cloakroom of the city's Cavern Club, where her musical talent was spotted by The Beatles.
Black had a string of hits starting in 1964 with "Anyone Who Had a Heart," written by Burt Bacharach and Hal David, and "You're My World." Both went to Number 1 in Britain, and the latter also charted in the US.
By the late '60s she was famous enough to be known by her first name alone, and hosted a BBC variety show, "Cilla".
With her reliable good cheer and tireless work ethic, Black was a TV natural. Her catchphrase - delivered in a strong Liverpool accent that replaced the letter "t" with "r" - was "a lorra, lorra laughs."
She became a British television fixture as the cheeky, cheery host of 1983 game show "Blind Date" and heartwarming-reunion program Surprise Surprise (between 1984 and 2001).
