Kitt described herself as a "sex kitten", while Orsen Wells, the 1930s actor-director, said she was "the most exciting women alive".
"I do not have an act. I just do Eartha Kitt," she told one British newspaper earlier this year.
"I want to be whoever Eartha Kitt is until the gods take me wherever they take me."
Andrew Freedman, her long-time friend and publicist, said: "She had been performing until two months ago... We had dates booked through 2009."
Kitt grew up on a deprived cotton plantation in a segregated South Carolina, but by the age of 20 had toured the world having started out with the Paris-based Katherine Dunham Dance.
The mixed-race singer performed C'est Si Bon and Old Fashioned Girl and a cover of Edith Piaf's La Vie en Rose.
Fans admired her portrayal of Catwoman in the US TV series Batman in the 1960s, and she had acted alongside Nat King Cole in 1958's St Louis Blues and Sidney Poitier in The Mark of the Hawk in 1957.
In 2000 she voiced the character Yzma in The Emperor's New Grove, a Disney animation, and three years later acted in the musical Nine on Broadway.
Her work continued towards and into her eighth decade with the sequel and TV series of The Emperor's New Grove, theatre work and cabaret shows.
Kitt won two Emmy television awards and was nominated for two Tonys and two Grammys.
She was married for five years in the 1960s to Bill McDonald, a real estate developer. The union produced one daughter, Kitt.