He was born into the aristocracy in Neuville-sur-Vanne in Champagne, France. He joined the military at the age of thirteen and had a successful career where he was noted for his ability and his piety. He was hired by Jérome le Royer de la Dauversiere, a Jesuit who was head of the Société de Notre Dame de Montréal. Based on a vision had by Royer de la Dauversiere, the society was attempting to build a mission on the Montreal Island in New France. Maisonneuve was hired to lead the colonists and ensure their security.
In 1641 he left from La Rochelle and after a difficult crossing of the Atlantic arrived in Quebec City and spent the winter there. There the governor attempted to dissuade the missionaries and Maisonneuve warning them of the danger of a settlement in the heart of Iroquois territory. Maisonneuve scoffed at the dangers and the next May he and the colonists left for the island.
There they founded Ville-Marie, building a chapel and a small settlement. A hospital under the command of Jeanne Mance was also established. They maintained peaceful relations with the Algonquins and the first year of the colony's existence was peaceful. In 1643 a flood threatened the city, Maisonneuve prayed to the Virgin Mary to stop the inundation and when it abated he erected a cross atop Mount Royal, and a cross remains there to this day.