Mario Beaulieu (; born 1959) is a Québécois nationalist. He was the interim leader (until 2019), president (2014–2019) and was also leader (2014–2015) of the Bloc Québécois. He was the president of the sovereigntist Société Saint-Jean-Baptiste of Montreal from 2009 to 2014, and has been the spokesman for the Mouvement Québec français.