The Beaver Lake (French: Lac aux Castors) is an artificial basin fitted in 1938 on a former swamp located on Mount Royal, in Montreal, Quebec, Canada.

The surroundings of the lake are equipped for various recreational activities: skating and sliding in the winter and vast lawns in the summer.

Built between 1956 and 1958 and inaugurated in 1961, the pavilion is located west of the lake.

Designed by architects Hazen Sise and Guy Desbarats of Montreal-based architectural firm Arcop, it was considered one of the most innovative buildings in Montreal, with a corrugated roof and large windows.

In 2007, the Ordre des architectes du Québec (Order of Architects of Quebec) awarded the Excellence Award in architecture to architects Pierina Saia and Réal Paul and to the City of Montreal for the conservation and heritage restoration of the Beaver Lake Pavilion.