Varennes is an off-island suburb of Montreal, in southwestern Quebec, Canada, on the Saint Lawrence River in the Marguerite-D'Youville Regional County Municipality. The city is approximately 24 kilometres (15 mi) from Downtown Montreal. The population as of the Canada 2011 Census was 20,994. In 2015, the population is listed at 24,000.

Greater Montreal is the most populous metropolitan area in Quebec and the second most populous in Canada after Greater Toronto. In 2015, Statistics Canada identified Montreal's Census Metropolitan Area (CMA) as 4,258.31 square kilometres (1,644.14 sq mi) with a population of 4,027,100, almost half that of the province.