On Wednesday, January 21, the Municipalité régionale de comte (MRC) d’Argenteuil Council announced significant population growth across all of its nine municipalities in 2025, citing the population data published in La Gazette officielle du Québec in late December 2025. The town of Brownsburg-Chatham led growth by adding 345 permanent residents in 2025, followed by the city of Lachute with an additional 216, contributing to MRC’s population rising by 844 individuals, or a 2.24 per cent annual increase, to a total population of 38,581.
Brownsburg-Chatham’s population increased to 8,491 from 8,146 in 2024, a rise of 4.23 per cent, while Lachute’s population increased to 15,508 from 15,292, a rise of 1.41 per cent. The combined population of Brownsburg-Chatham and Lachute accounts for 66.21 per cent of the region’s total population.
Third in growth was Gore Township, which added 79 permanent residents in 2025, increasing its population to 2,765, while Mille-Isles added 55 residents, raising its population to 1,893.
Saint-André-d’Argenteuil recorded a population increase of 52 individuals, raising its population to 3,309, while the Village of Grenville added 30 residents, raising its population to 1,896. Grenville-sur-la-Rouge reported adding 10 residents, bringing its population to 3,050.
The Township of Harrington added 25 permanent residents, raising its population to 979, while the Township of Wentworth added 22 residents, bringing its population to 689.
Population growth across all nine municipalities underscores a continued trend of development and expansion within the MRC d’Argenteuil. These figures reflect steady growth, highlighting the region’s ongoing population increase.
