He was born in Verchères, Lower Canada in 1823, grew up in Laprairie and studied at the Petit Séminaire de Montréal.

Fortin also served as customs agent in the Gulf and, with his ship, La Canadienne, was the sole guardian of law and order in this region.

He was named commissioner of crown lands in the provincial executive council but resigned in 1874 after a scandal implicating the party in power.

While in office, he helped promote the development of the Baie de Chaleur Railway, telegraph service connecting the Gaspé peninsula to the rest of the province and the installation of lighthouses in the region.

In 2002, the Quebec Ministère des Ressources naturelles et de la Faune named a wildlife reserve on the Richelieu River after Pierre-Étienne Fortin.