Juliette Gréco, an acclaimed French chanteuse whose sensual stage mystique and doleful voice bewitched audiences for more than six decades and made her an international recording and concert star, died Sept. 23 at her home in Ramatuelle, France.

She was 93 and was one of the last links to Jean-Paul Sartre and other existentialist intellectuals who made her their raven-haired, black-clad muse in the post-World War II bohemia of Paris’s Saint-Germain-des-Prés neighborhood. Her death was widely reported by French media, but information on the cause was not immediately available.

In her music, Ms. Gréco conveyed an intense world-weariness that was a bittersweet reflection of her life. She had been on her own from the age of 16, when the Gestapo deported her mother, a member of the French Resistance during World War II, to a concentration camp.

Ms. Gréco made her way to Paris and kept company with writers and artists, including Sartre, Simone de Beauvoir, Jean Cocteau and Albert Camus. They held court in smoke-filled bars and cafes until dawn and adopted Ms. Gréco as one of their own. Her spellbinding voice, husky and intimate, moved Sartre to write songs for her, calling them “lusterless” words that became “precious stones” in her mouth.

Ms. Gréco also turned heads with her looks — her high cheekbones and her deep-set, almond-shaped eyes. Leading French photographers such as Henri Cartier-Bresson and Robert Doisneau captured her as an incandescent, waifish beatnik, the embodiment of Left Bank chic.

Onstage, she was wild, tangled tresses, kohl-rimmed eyes, sleek black pants and turtleneck sweaters. “You moonbathe while others sunbathe,” Pablo Picasso reputedly told her, a reference to her alabaster skin against her jet-black ensemble.

Ms. Gréco had leading roles in European and American films in the 1950s, though Hollywood mogul Darryl F. Zanuck, one of her lovers, failed miserably at turning her into a movie star. But she remained a major cabaret attraction, popularizing Jacques Prévert’s “Je Suis Comme Je Suis” (“I Am What I Am”), his haunting “Les Feuilles Mortes” (known in English as the standard “Autumn Leaves”) and his “La Belle Vie” (“The Good Life”), with its sorrowful words, “In the menagerie there are animals that spend all their life behind bars, and us, we are the brothers of this poor livestock . . . and we turn in circles, not seeing the landscape, not singing songs.”

Raymond Queneau’s “Si Tu T’Imagines” (“If You Can Imagine”), in which a woman imagines her physical beauty deteriorating, became another of Ms. Gréco signature tunes. As an established star, she later boosted the careers of aspiring singer-songwriters Charles Aznavour (“Je Hais les Dimanches” (“I Hate Sundays”) and Serge Gainsbourg (“La Javanaise”).

Thrice married, Ms. Gréco conducted romances with Gainsbourg, ill-fated racecar driver Jean-Pierre Wimille and crooner Sacha Distel. Most famously, she indulged in a torrid affair in 1949 with visiting American jazz trumpeter Miles Davis, despite their lack of a common language. “I caught a glimpse of Miles, in profile,” she later said. “A real Giacometti, with a face of great beauty.”

Davis was equally transfixed.

“Juliette and I used to walk down by the Seine River together, holding hands and kissing, looking into each other’s eyes, and kissing some more, and squeezing each other’s hands,” he wrote in his memoir. “It was like magic, almost like I had been hypnotized, was in some kind of trance.”

Ms. Gréco said she wanted to follow him back to the United States, but he cut short the liaison because he feared that her career, in the era of segregation, would be destroyed by her association with a Black man. “Sartre asked Miles why we didn’t get married, but Miles loved me too much, he said, to marry me,” she told the Guardian newspaper.

She had no use for possessiveness in friends, lovers or artistic contracts. She showcased her grit in 1981 by agreeing to perform at a gala, televised live, in Chile for dictator Augusto Pinochet and throngs of military officers and their wives, and then giving a concert of songs that had been banned by the junta.

“I came on stage to a tumultuous reception,” she said to the London Independent years later. “I went off to dead silence. That silence was one of the greatest triumphs of my career.”

Juliette Gréco was born Feb. 7, 1927, in Montpellier, on the Mediterranean coast of France, the younger of two daughters of ill-matched parents. Her father, a police superintendent, had a violent temper. Her mother, an aspiring artist, was decades younger than her husband and considered her children a burden.

She offloaded the children on her parents in Bordeaux, but they eventually wound up back in her care in Paris. Ms. Gréco became a promising ballet pupil, but that came to an end at the start of the German occupation in 1940. Three years later, her mother and older sister, who were active in the Resistance, were detained by the Gestapo and deported to the Ravensbrück concentration camp, about 50 miles from Berlin.

Ms. Gréco spent time in Fresnes prison, outside Paris, before she was released because of her age. The thin blue dress and raffia sandals she was wearing when she was arrested were her only remaining possessions. She walked to Paris in freezing temperatures and was nursed back to health by an actress friend of her mother’s.

A postwar reunion with her family was short-lived and wounding; her mother barely acknowledged Juliette and soon left for a career in the women’s naval service — an abandonment Ms. Gréco never entirely forgave.

After arriving in Paris, she scrounged for work and food while taking acting classes with the ambition of becoming a great stage tragedienne. Over the next year or two, before Ms. Gréco began singing professionally, her striking beauty made her a popular subject for photographers chronicling the Left Bank’s postwar bohemian atmosphere. In 1947, a photo by Carl Perutz for Life magazine captured her in borrowed men’s clothes — baggy trousers and an old sweater she rolled up at the sleeves — and set off a brief fashion trend.

Ms. Gréco made a name for herself as a hostess at Le Tabou, which became a favored haunt of Paris’s intellectual and cultural crowd, from Beaux-Arts students to Picasso. “Juliette Gréco reigned there by her sheer presence,” Cocteau later said. Having sung at parties, she made her professional debut at a different nightclub in 1949. Sartre contributed songs, including “La Rue des Blancs-Manteaux.”

The next year, Cocteau persuaded her to appear in his film “Orpheus,” a masterpiece that set the Greek myth in contemporary Europe. Ms. Gréco played the leader of a feminist group.

But her appeal to concert audiences did not always translate well to the big screen. Her first leading role, in “When You Read This Letter” (1953), drew a scathing review from Les Cahiers du Cinema: “She states banalities in a tragic voice and tragic things with banality.” Ms. Gréco’s brief marriage to her co-star, Philippe Lemaire, produced her only child, daughter Laurence-Marie, who died in 2016.

Ms. Gréco was pursued personally and professionally by Zanuck, who had been struck by a photo of her in a magazine. He had her nose straightened and her hair lightened, and he cast her in a small role as a cabaret singer in his adaptation of Ernest Hemingway’s “The Sun Also Rises” (1957). His attempts to build her into a major star were a disaster, including risible melodramas featuring a dissipated Errol Flynn (“Roots of Heaven” in 1958) and a bloated Orson Welles (“A Crack in the Mirror” in 1960). When the affair cooled, so did her movie career.

She remained at the height of her musical stardom over the next decade, filling theaters and captivating reviewers with Gainsbourg’s “L’Accordeon” (in performance, she would flutter her fingers over her body as if it were an accordion) and Robert Nyel’s frank “Deshabillez-moi” (“Undress Me”).

“She grasps each song and wrings every ounce of feeling from it,” the Guardian’s Robin Denselow wrote after a London engagement. “Each one is acted out to the full. She is sexy, funny, sad, and thoroughly exhausting.”

Privately, Ms. Gréco struggled with depression and attempted suicide in 1965 by taking an overdose of sleeping pills. The next year, she married French film star Michel Piccoli, a union that ended in divorce about a decade later. She and Gérard Jouannest, a composer and pianist, were married from 1988 until his death in 2018. Complete information on survivors was not immediately available.

Ms. Gréco suffered a heart attack in 2001 and continued to perform after a stroke in 2016. Music provided catharsis, she once told the Times of London. “On the concert stage is where I forget everything,” she said. “It’s better to be far away from an audience, because then there are no limits — you can go very far. It’s a marvelous freedom — you can say anything. But if they are too close to me, then I don’t dare. I am extremely pudique — reserved, if you like. When I am far away I can suggest I am nude.”