Born in Verchères on December 12, 1957, Pierre Moreau obtained a Bachelor of Civil Law from Laval University in 1980 and was admitted to the École du Barreau du Québec in 1981.
He spent 22 years specializing in municipal and administrative law in a private practise in Montreal. He also shared his expertise by teaching at the École du Barreau du Québec from 1996 to 2002.
He first entered the political arena by running for the Liberal Party of Quebec in October 2002. Elected as Member of National Assembly for Marguerite-d’Youville on April 14, 2003, he successively served as parliamentary assistant to the Minister of Justice and Attorney General, as assistant Government House Leader, and as parliamentary assistant to the Chair of the Conseil du trésor and Minister responsible for Government Administration.
In 2007 and 2008, Pierre Moreau held the offices of Chief of staff for the Government House Leader, and as Chief of staff for the Minister of Justice and Attorney General and the Minister of Public Security.
Elected as MNA for Châteauguay in the general election held on December 8, 2008, he held the offices of Chief Government Whip from December 2008 up until February 2011 and from February to September 2011, of Minister responsible for Canadian Intergovernmental Affairs and the Canadian Francophonie, and of Minister responsible for the Reform of Democratic Institutions and Access to Information. He was then appointed as Minister of Transports from September 2011 to September 2012.
Pierre Moreau was, re-elected as MNA for Châteauguay in the general election held on September 4, 2012 and appointed as Official Opposition House Leader on April 9, 2013.