Area codes 450, 579, and 354 are telephone area codes in the North American Numbering Plan in the Canadian province of Quebec, encompassing the off-island suburbs of Montreal, as well as the rest of the Montérégie region southward to the border with New York state. Among the cities in the numbering plan area are Laval, Longueuil, Terrebonne, Saint-Jean-sur-Richelieu, Brossard, Repentigny, Saint-Jérôme, Granby, Blainville and Saint-Hyacinthe.

Laval is a city in Quebec, Canada. It is in the southwest of the province, north of Montreal. It is the largest suburb of Montreal, the third-largest city in the province after Montreal and Quebec City, and the thirteenth largest city in Canada, with a population of 443,192 in 2021.