Westmount Square is a residential and office complex located in Westmount, Quebec, Canada. There are two of residential apartment buildings, and two office buildings. These towers sit atop an underground shopping centre consisting of thirty-five shops. It is located between Saint Catherine Street and De Maisonneuve Boulevard and between Wood Avenue and Greene Avenue. It is connected to Place Alexis Nihon and the Atwater Metro station by an underground tunnel.
The complex was designed by architect Ludwig Mies van der Rohe in the International style. Construction began in 1964 and the complex opened on December 13, 1967. The exterior facade features curtain walls, and is made of black anodized aluminum and smoked glass windows. It was modeled on Lake Shore Drive Apartments in Chicago.
The office building, also known as Tower 1, has 22 floors and stands 83 metres (272 ft) tall. The other office building has 2 floors and is known as the Tower 4 Pavilion; it was formerly the Eastern Airlines Building. The two residential towers each have 21 floors, and stand 69 metres (226 ft) tall.
Westmount Square's shopping concourse houses boutiques and art galleries, with about one-third of the space reserved for private for-profit health clinics. Skylights were installed on the roof of the shopping concourse in 1990, which led to criticism among architectural preservationists.
The entrance to the shop gallery, on Greene Avenue, was formerly decorated by a sculpture, The Chorus, by Sylvia Lefkovitz.