French media said Greco died aged 93 at her Ramatuelle house in the south of France, near Saint Tropez.
The mayor of Nice, Christian Estrosi, tweeted that “a very grand lady, an immense artist has gone”.
With expressive eyes inherited from her Greek ancestors and an impossibly deep, raspy voice – acquired from years of cigarette-smoking – Greco immortalized some of France’s most recognizable songs in an enduring seven-decade career, including the classics Soul le ciel de Paris (Under the Parisian sky) and Je hais les dimanches (I hate Sundays).
Greco was born in Montpellier on February 7, 1927, to an absent father, Gerard Greco, and a mother from Bordeaux, Juliette Lafeychine — from whom, she told a 1986 French documentary, she received little love.
“You are not my daughter,” Greco quoted her mother as saying.
After a lonely childhood, Greco became a devotee of bohemian trends among intellectuals in post-war France, beginning as an actress in Paris in 1946.
It was in the artistic hub of the Left Bank that she met philosopher Jean-Paul Sartre, who famously said she had “millions of poems in her voice”.
She knew many of the writers and artists working in Saint-Germain-des-Pres, such as Albert Camus, Jacques Prevert, Jean Cocteau and Boris Vian, and gained the popular nickname “the muse of existentialism”.
Artistically, Greco flourished upon meeting Serge Gainsbourg in the late 1950s, then a young musician whose talent was revitalising French song.
Gainsbourg wrote her songs for five years from 1959 and she recorded 10 of them, including La Javanaise (The woman from Java) which earned her considerable acclaim.
A fashion icon whose bobbed hair, Cleopatra-style eye-lines and austere black clothes became synonymous with the France of May 1968, Greco became a role model to many, including British Swinging Sixties icon, singer and feminist Marianne Faithfull, who was quoted as saying: “If I want to be anybody, I want to be Juliette Greco.”
Sir Paul McCartney said in a 2007 interview that the Beatles’ 1965 classic Michelle was inspired by Greco, who epitomised the cool of the era far beyond France.
“We’d tag along to these parties, and it was at the time of people like Juliette Greco… So I used to pretend to be French, and I had this song that turned out later to be ‘Michelle’,” he said.
Greco was married three times: To actor Philippe Lemaire with whom she had one daughter, Laurence-Marie Lemaire, to French movie star Michel Piccoli from 1966 to 1977, and to pianist Gerard Jouannest from 1988 till his death in 2018.
She was known as much for her liaisons with famous men as she was for her music. She was linked to a number of prominent intellectuals and musicians including Nobel literature laureate Camus, jazz trumpeter Miles Davis and jazz composer Quincy Jones.
In March, 2016, Greco suffered a stroke while she was stopping off in Lyon as part of her tour, and cancelled the rest of her concerts.
It was the same year that her only daughter, Laurence-Marie, died of cancer.
