Thérèse Joyce-Gagnon was born in Montréal. She studied at the Montréal School of Fine Arts and at the Université du Québec à Montréal (UQAM).
She has participated in the career management course at the Hautes Études Commerciales part of L'Université de Montréal and a number of summer sessions as artist-in-residence at the Banff Centre for the Arts, Alberta.
She has received scholarshipd from the Canada Council for the Arts, the Conseil des Arts et des Lettres du Québec, the Québec Ministry of Culture and the Banff Centre for the Arts. She was also awarded a residential scholarship from the City of Dinan in France.
She has had numerous group exhibitions in Québec, Ontario, Alberta and France. She was President of the Conseil de la Peinture in 1991-1992 and in 1994-1995, she became President of the Regroupement des Artistes en Arts Visuels du Québec.
Her works are regularly shown in private viewing and are also part of many public and private collections.
She currently lives and works in Montréal. Her work focuses on the human figure and fragmentation as essential aspects of research in her artistic processes'. Much of her career was focused on portrait painting, more recently her work in concerned with juxtapozing on canvas heterogeneous elements. She alternates between portrait and assemblage.