Joseph Joffo was born to a Jewish family in Paris, France. When he was 10 years old, near the start of the Nazi Occupation of his homeland in World War II, his father gave him and his brother Maurice, age 12, 5,000 francs each and instructions to flee to join their older brothers Henri and Albert in Menton in the French southern zone. The two boys managed to evade the Nazis and spent four months with Henri and Albert, before having to flee again to Nice. After the liberation of Paris in 1944,
Joseph returned to the city to join his brothers working in the family barbershop, although without their father Roman, who died in a Nazi concentration camp. His highly-popular memoir Un sac de billes (A Bag of Marbles), written as a novel, was published in 1973 and has sold 20 million copies. It was adapted twice into French films, in 1975 and again in 2017, and into a graphic novel. Other works include Anna et son orchestre (Anna and Her Orchestra, 1970), telling the story of Joseph's mother from childhood to the time she met his father; Baby-foot (1977), a sequel to Un sac de billes that describes Joseph's life in Paris following the war;
La Vieille dame de Djerba (The Lady of Djerba, 1984).