Before 1961, seven separate communities existed to form what is today known as Longueuil. They merged over the following decades, and Longueuil reached its current state. This section lists a series of
mergers involving Longueuil. In
italic is the surviving municipality.
1961-1969 On January 28, 1961, these communities merged, keeping Longueuil's namesake: •
Longueuil •
Montréal-Sud 1969-2001 In 1969, Longueuil merged again with another neighbouring city: •
Longueuil •
Ville Jacques-Cartier In October, 1971, neighbouring Saint-Hubert had a merger as well: •
Saint-Hubert •
Laflèche 2002-2005 On January 1, 2002, Longueuil and seven other
south shore municipalities merged: •
Longueuil •
Boucherville •
Brossard •
Greenfield Park •
LeMoyne •
Saint-Bruno-de-Montarville •
Saint-Hubert •
Saint-Lambert 2006-present On January 1, 2006, four of the municipalities previously merged in 2002 voted to secede from Longueuil: •
Boucherville •
Brossard •
Saint-Bruno-de-Montarville •
Saint-Lambert Therefore, Longueuil is currently composed of: •
Longueuil •
Greenfield Park •
LeMoyne •
Saint-Hubert ==List of mayors ==