Born in Saint-Charles-de-Bellechasse, Quebec, Lapierre started out in politics as city councillor in Beaumont, Quebec in 1971. In 1974 he became mayor where he remained until 1985. After a nine-year hiatus, he was elected mayor again, which he remained until 2004. From 2001 to 2004 he was also a prefect in the Bellechasse MRC. In the 2004 Canadian federal election, he was elected into the House of Commons of Canada as a Bloc Québécois member in the riding of Lévis—Bellechasse. He was defeated in the 2006 election.