Concordia University (French: Université Concordia), commonly referred to as Concordia, is a public comprehensive research university located in Montreal, Quebec, Canada. Founded in 1974 following the merger of Loyola College and Sir George Williams University, Concordia is one of the three universities in Quebec where English is the primary language of instruction (the others being McGill and Bishop's). As of the 2020–21 academic year, there were 51,253 students enrolled in credit courses at Concordia, making the university among the largest in Canada by enrolment. The university has two campuses, set approximately 7 kilometers (4 miles) apart: Sir George Williams Campus is the main campus, located in the Quartier Concordia neighborhood of Downtown Montreal in the borough of Ville Marie; and Loyola Campus in the residential district of Notre-Dame-de-Grâce. With four faculties, a school of graduate studies, and numerous colleges, centers, and institutes, Concordia offers over 400 undergraduate and 200 graduate programs and courses.

The university's John Molson School of Business consistently ranks among the top 10 Canadian business schools and the top 100 worldwide. Moreover, Concordia was ranked seventh in Canada and 229th among world universities in the International Professional Classification of Higher Education Institutions.

The university is a member of the Association of Universities and Colleges of Canada, International Association of Universities, Canadian Association of Research Libraries, Canadian University Society for Intercollegiate Debate, Canadian Bureau for International Education, and Canadian University Press. The university's varsity teams, known as the Stingers, compete in the Quebec Student Sports Federation of U Sports.