Châteauguay is an off-island suburb of Montreal, in southwestern Quebec, located both on the Chateauguay River and Lac St-Louis, which is a section of the St. Lawrence River. The population of the city of Châteauguay as of the 2011 Census was 45,904, and the population centre was 70,812.

The land was first given to Charles Lemoyne by the governor of New France at the time, the Comte de Frontenac with the intention of setting up a seigneurie in the area. Afterwards the seigneurie was assumed by Zacharie Robutel de la Noue in 1706. In 1763 France relinqueshed its claims in Canada and Châteauguay was now under British mandate. The seigneurie was bought by Marguerite d'Youville, a founder of the Quebec religious society the Grey Nuns in 1765 and 10 years later construction began on the Church of Saint-Joachim.

Châteauguay played an important part in the colonial history of North America. With the United States having declared war on Britain in 1812, Châteauguay was seen as little more than a good vantage point to post troops to defend Montreal against an invasion. This prong of the American advance on Montreal ended with the Battle of the Châteauguay, where on October 25, 1813 Lieutenant Colonel Charles de Salaberry succeeded in halting the American force of 4,000 advancing on Montreal with only some 400 troops, mostly French-Canadian and 170 Kahnawake Mohawk warriors. The second American incursion towards Montreal was defeated shortly after at Crysler's Farm on November 11.

Joseph Allard (December 31, 1910 – May 3, 1991), a native of Lowell, MA, was a professor of saxophone and clarinet at the Juilliard School, the New England Conservatory, the Manhattan School of Music, as well as adjunct positions at many other schools. He succeeded saxophonist/clarinetist Vincent J. Abato at Juilliard and was the saxophone instructor there from the 1956-57 school year until the end of the 1983-84 year. He was the first saxophonist with the NBC staff orchestra in New York City. He played the "Firestone Hour" and "Bell Telephone Hour" on TV and radio, as well as bass clarinet in the NBC Symphony Orchestra under Arturo Toscanini from 1949-54. He played with Red Nichols and the Five Pennies, and for a brief period played with Red Norvo's orchestra.

Among his famous students are Michael Brecker, Eddie Daniels, Bob Berg, Dave Liebman, Paul Winter, Victor Morosco, Eric Dolphy, Harvey Pittel, Col Loughnan and Kenneth Radnofsky. Joseph was the coach for the saxophone section in Glenn Miller's Orchestra as well as Benny Goodman's Orchestra.

Sylvain Chicoine is a Canadian politician, who was elected to the Canadian House of Commons in the 2011 election. He represents the electoral district of Châteauguay—Saint-Constant as a member of the New Democratic Party.

Prior to being elected, Chicoine worked as a Special Constable at the Université de Montréal. He has a diploma in police technology from Collège de Maisonneuve.