Collège Ste-Marie was founded by Jesuits in 1848. It had an English sector (which called the school St. Mary's College) that later became separate in 1896 as Loyola College. Ste-Marie was never a degree issuing institution, instead, relying on its affiliation with chartered universities to grant degrees. Despite this, it had full curriculum control. Ste-Marie was originally affiliated with Université Laval until 1920, when it was affiliated with Université de Montréal. The college originally offered primary and secondary (elementary and high school level) education as well as collegial studies.
A portion of the original college remains as the Église du Gesù (Church of Gesu, named after the church where St. Ignatius of Loyola is buried), which was originally the college chapel. Built in 1865 and designed by Irish architect Patrick Keely, it is one of the oldest religious buildings in Montreal. Also housed in the structure is the Salles du Gesù, Montreal's oldest theatre.