Born in Paris, France to a wealthy French family, Aumont began studying drama at the Paris Conservatory, following his mother, at the age of sixteen. His professional stage debut occurred at the age of 21. His film debut came one year later, when Jean de la Lune (Jean of the Moon in English) was produced in 1931. However, his most important, career-defining role came in 1934, when Jean Cocteau's play La Machine Infernal (The Infernal Machine) was released in 1934.
However, right when his film and stage career began rising quickly, World War II broke out. Aumont stayed in France until 1942, when he realized that because of his Jewish ancestry, he would be forced to flee from the Nazi forces. He first fled to an unoccupied portion of Vichy territory, before moving, first to New York City, then Hollywood to further his film career. He began working with MGM; however, he was not content with staying in the safe United States while his fellow countrymen were fighting for their lives in Europe. Therefore, after finishing his film, The Cross of Lorraine (which was highly liked by certain Resistance leaders, including Charles de Gaulle), he joined the Free French.
After the completion of the film, Aumont was sent to North Africa, where he participated in Operation Torch, specifically in the country of Tunisia. Then, he moved with the Allied armies through Italy and France. Through the war, he was wounded twice. The first was on a mission with his brother. However, the second was more serious. Aumont's Jeep was blown up near a mined bridge, and French Brigadier General Diégo-Charles-Joseph Brosset, commander of the 1st Free French Division, was killed. Because of his bravery during the fighting, Aumont received the Legion d'Honneur and the Croix de Guerre.
While in Hollywood, though, Aumont married Maria Montez, a Dominican actress. She was known as the "Queen of Technicolor", and their marriage was very happy; however, she tragically drowned and died on September 7, 1951, in the family's villa at Suresnes, France. Aumont kept working after his wife's death, though, starring as the magician in the extremely successful film, Lili, with Leslie Caron. In 1956, he married Italian actress Marisa Pavan, star of various films including The Man in the Grey Flannel Suit. The couple starred in one film together, John Paul Jones, where Pavan played the romantic interest of the lead, while Aumont cameoed as King Louis XVI. However, the couple divorced in 1962, but rejoined a short while later. They had two children: Jean-Claude and Patrick, and lived a rather happy life.
Aumont continued working with various famous actors and directors. In the 1960s, he starred in various Broadway productions. He starred in many films throughout the latter half of the 20th century, and one of his more recent works was released in 1989, A Tale of Two Cities. Two years afterward, he was decorated with the cross of Commandeur des Arts et des Lettres, and in 1992, he received an honorary César Award. Aumont was also a distinguished author, although the English translations of his works were sub-par. When he died in 2001, Aumont was one of the most distinguished and famous French actors of the 20th century.