Jean Drapeau was born on February 18, 1916, in Montreal, Quebec, Canada, to Joseph-Napoléon Drapeau and Alberta (Berthe) Martineau. His father, an insurance broker, city councilor, and election worker for the Union nationale, introduced him to politics from a young age.
Drapeau studied law at the Université de Montréal and later became a criminal lawyer in Montreal in 1944. He married Marie-Claire Boucher in 1945 and had three sons with her.
Jean Drapeau's profile grew significantly as a result of his role in a public inquiry led by Pacifique Plante into police corruption in the early 1950s. When Camillien Houde retired as mayor of Montreal, Drapeau was well-poised to succeed him.
Drapeau was elected mayor of Montreal in 1954 at the age of 37 as the candidate of the Civic Action League on a platform of cleaning up the administration. He ran an exceptionally wide-flung campaign, uniting a large coalition of voters from English-speaking and French-speaking parts of Montreal.
Drapeau's charisma, accessible style, and fluency in both English and French propelled him to popularity. He was re-elected without interruption until he retired from political life in 1986.
During his tenure as mayor, Drapeau oversaw the development of the Montreal Metro, a successful international exposition, Expo 67, and the construction of a major performing arts centre, the Place des Arts.