Greenfield Park is a former city in southwestern Quebec, Canada. It is currently a borough of the city of Longueuil. It covers an area of 4.78 square kilometres (1.85 sq mi), with a population of 16,733 at the 2016 census of Canada. Greenfield Park is the only borough of Longueuil that has an officially bilingual status. It is primarily a post-WWI suburban area. Like the other two boroughs, most of the buildings in Greenfield Park are single-family homes. Nearly all of the land in Greenfield Park is built on, making it Longueuil's most densely populated borough.

Longueuil is a city in the province of Quebec, Canada. It is the seat of the Montérégie administrative region and the central city of the urban agglomeration of Longueuil. It sits on the south shore of the Saint Lawrence River directly across from Montreal. The population as of the Canada 2021 Census totalled 254,483, making it Montreal's second largest suburb, the fifth most populous city in Quebec and twentieth largest in Canada.