Borduas was born in Saint-Hilaire, Quebec. At the age of sixteen he became an apprentice to Ozias Leduc, a church decorator. Leduc gave Borduas a basic artistic training, teaching him how to restore and decorate churches. In 1923, assisted by a scholarship Leduc had secured for him, he enrolled in the École des Beaux-Arts in Montreal, continuing to work for Leduc at the same time. Upon his graduation in 1927 he was hired by the Montreal Catholic School Board as a high school art teacher. In January of 1929 he began studies at the Atelier d'Art Sacree in Paris, which he abruptly left in April of that year. He returned to Saint-Hilaire in June of 1930, began teaching part time, and in 1933 returned to teaching high school for the Catholic School Board of Montreal. In 1937 he began teaching at the Ecole de Meuble, where he met John Lyman.
Lyman encouraged Borduas' involvement with the Contemporary Arts Society, and in January of 1938 he was elected vice-president of the group. In 1941 he resumed painting after several years of study and teaching, during which time he and a group of students had met regularly to discuss recent trends in European art. His first abstract paintings date from this year, and in April of 1942 he exhibited forty-five gouaches inspired by the abstract surrealism of Joan Miro. He became increasingly involved with about a dozen of his students, and they became known collectively as the Automatistes for their attempts to paint with pure psychic automatism per the writings of Andre Breton. In January of 1946, the first group exhibit of Borduas and his students was held in New York City, followed in April by an exhibit in Montreal. This was the first exhibit by a group of abstract painters in Canada. A second Montreal exhibit followed in February-March of 1947. A critic, responding to this exhibit, coined the name "Automatists" for the group, after Borduas' painting Automatisme 1.47. He wrote Le Refus Global in late 1947- early 1948, an important manifesto that advocated the separation of church and state in Quebec, especially for the arts. The manifesto considered one of the primary causes of the Quiet Revolution in Quebec. Four hundred copies went on sale on August ninth, 1948. Borduas was dismissed from the Ecole du Meuble on September second.
In 1955 he moved back to Paris where he died of a heart attack in 1960.