Gilles Mathieu was born on January 18, 1933 in Lachine, on the island of Montreal. He spent all his summers in the Laurentians and in 1942, his family moved to Val-David. His father opened a workshop manufacturing doors and windows. From the age of 10 to 14, Gilles attended the tiny village school.
Back in Montreal, he studied graphic arts at Studio A. Salette and attended the École des Beaux-Arts and the École du meuble. From the age of 16 to 26, with an accordion under his arm, he was a member of the folklore troupes L’Ordre du bon temps and Les Troubadours neufs. In all the places they played, Québec culture was starting to boil over. He met Félix Leclerc, Gaston Miron, Claude Léveillée, René Derouin, Armand Vaillancourt and others, and became part of this youthful circle that was busy participating in the hopeful birth of a nation.
In 1959, while working as a graphic designer at the Desmarais printing company in Montreal, he continued to visit Val-David on weekends. For Val-David youth and the tourists passing through the Laurentians, there was nothing much to do on Saturday nights. 26-year-old Gilles decided to try and liven the place up. He converted a chicken coop into a sort of café-théâtre. Thus was the Butte à Mathieu born, at the bottom of the hill to begin with, and destined to become one of the most powerful cultural leaders of the Quiet Revolution.