The son of an insurance company president, Yves Saint-Laurent was born on 1 August 1936 in Oran, in what was then French Algeria. Saint Laurent left home at the age of 17 to work for the French designer Christian Dior. Following Dior's death in 1957, Yves, at the age of 22, was put in charge of the effort of saving the Dior house from financial ruin.

Shortly after this success, he was coned to serve in the French army during the Algerian War of Independence. After 20 days, the stress of being hazed by fellow soldiers led the fragile Saint Laurent to be institutionalized in a French mental hospital, where he underwent psychiatric treatment, including electroshock therapy, for a nervous breakdown.

In 1962, in the wake of his nervous breakdown, Saint Laurent was released from Dior and started his own label, YSL, financed by his companion, Pierre Bergé. The couple split romantically in 1976 but remained business partners. During the 1960s and 1970s, the firm popularized fashion trends such as the beatnik look, safari jackets for men and women, tight pants and tall, thigh-high boots, including the creation of arguably the most famous classic tuxedo suit for women in 1966, Le Smoking suit. He also started mainstreaming the idea of wearing silhouettes from the 1920s, '30s and '40s. He was the first, in 1966, to popularize ready-to-wear in an attempt to democratize fashion, with Rive Gauche and the boutique of the same name. He was also the first designer to use black models in his runway shows. Among his muses were Loulou de la Falaise, the daughter of a French marquis and an Anglo-Irish fashion model; Betty Catroux, the half-Brazilian daughter of an American diplomat and wife of a French decorator; Talitha Pol-Getty, who died of drug overdose in 1971; Catherine Deneuve, the iconic French actress; and the Guinean-born Senegalese supermodel Katoucha Niane, the daughter of writer Djibril Tamsir Niane. Ambassador to the couturier during the late 1970s and early 80s was London socialite millionairess Diane Boulting-Casserley Vandelli, making the brand ever more popular amongst the European jet-set and upper classes.

In 1983, he became the first living fashion designer to be honored by the Metropolitan Museum of Art.

In 2001, he was awarded the rank of Commander of the Légion d'Honneur by French president Jacques Chirac.

Saint Laurent retired in 2002 and became increasingly reclusive. From then until his death he spent much of his time at his house in Marrakech, Morocco.

He also created a foundation with Pierre Bergé in Paris to trace the history of the house of YSL, complete with 15,000 objects and 5,000 pieces of clothing.

He died on June 1, 2008, in his home in Paris of a long-term illness.