Mario A. Beaulieu[3] MP (French pronunciation: [maʁjo boljø]; born February 1, 1959) is a Canadian politician.

He was the 80th president of the sovereignist Société Saint-Jean-Baptiste of Montreal from 2009 to 2014 and has been a spokesman for the Mouvement Québec français, a coalition of organizations in favour of the preservation and defence of the French language in Quebec.

In April 2014, he declared his candidacy for the leadership of the Bloc Québécois and received the endorsement of the executive of the Bloc's youth wing,[5][6] former Parti Québécois legislative members Bernard Landry and Pierre Curzi, and the former president of the Mouvement Desjardins, Claude Béland.

"[11] On August 25, 2014, André Bellavance, who had lost to Beaulieu in the leadership vote also resigned, reducing the Bloc to two MPs.

[12] Bellavance told a press conference, in regards to Beaulieu: "His vision and orientation for the Bloc are diametrically opposed to mine.

Beaulieu was named interim leader after Ouellet resigned over losing a party referendum on her leadership.