Arcop was an architectural firm based in Montreal, renowned for designing many major projects in Canada including Place Bonaventure, Place Ville-Marie and Maison Alcan. The firm was originally formed as a partnership under the name Affleck, Desbarats, Lebensold, Michaud & Sise between Ray Affleck, Guy Desbarats, Jean Michaud, Fred Lebensold and Hazen Sise, all graduates and/or professors at the McGill School of Architecture. In 1959, after the departure of Michaud and the addition of Dimitri Dimakopoulos, another McGill Architecture graduate, the firm was renamed Affleck, Desbarats, Dimakopoulos, Lebensold, Sise which it maintained for a decade afterward. The company did not adopt the name Arcop, which stands for "Architects in Co-Partnership", until 1970.