Bujold was born in Montreal, Quebec, the daughter of Laurette (née Cavanagh), a maid, and Joseph Firmin Bujold, a bus driver. She is of French Canadian descent, with distant Irish ancestry. Bujold received a strict convent education before entering the Montreal Conservatory of Dramatic Art, where she was trained in the classics of French theatre. She made her stage debut as Rosine in Le Barbier de Séville in 1962.