Born in Paris on October 10, 1610, Gabriel Lalemant was educated at the Jesuit College de Clermont. He entered the Jesuit novitiate in Paris when he was twenty years old, and made profession of vows two years later, on March 25, 1632. At this time, he also made a vow to devote himself to the foreign missions.
After his profession, because of ill health, Lalemant taught classics and theology at Moulins, and was chaplain at the Jesuits' college in La Fleche. For two years, he was superintendent of studies at the Jesuits' college in Bourges. Finally, in 1646, he was appointed to the Huron missions, where, coincidentally, his uncle was superior. He arrived in Quebec on September 20, 1646, and spent the next two years learning the language and customs of the Huron tribes.
Lalemant arrived in Sainte Marie, the mission headquarters in September 1648, and became the companion of Jean de Brébeuf on weekly visits to the missions among the Hurons.
On March 15, 1649, Iroquois stormed the village of Saint Ignace; the two Jesuits were taken prisoner. Lalemant died two days later as a result of the torture they endured.
Gabriel Lalemant was beatified by Pope Pius XI on June 21, 1925, and canonized by the same Pope on June 29, 1930.