Marc Tanguay MNA (born April 18, 1973) is a Canadian politician and a member of the National Assembly of Quebec for the LaFontaine electoral district.

On September 26, 2009, he was elected president of the Quebec Liberal Party.

He was elected in a by-election held on June 11, 2012, which was triggered by the resignation of Tony Tomassi on May 3, 2012.

Prior to that, he was an unsuccessful Liberal candidate in the 2007 general election in Chambly electoral district, finishing third.

[2] On November 10, 2022, he was named interim leader of the Quebec Liberal Party following the resignation of Dominique Anglade.