Longueuil is a city in extreme southwestern Quebec, Canada, on the south shore of the Saint Lawrence River across from Montreal, of which it is a suburb. Residents of Longueuil are called Longueuillois. In 2006, the population of the new city of Longueuil totaled 229,330, making it the fifth largest city in Quebec and 19th largest in Canada. The current city has an approximate land area of 115.59 km².