Legault was a MNA from 1998 to 2009—serving in the governments of former premiers Lucien Bouchard and Bernard Landry— as the minister of education from 1998 to 2002 and as the minister of health from 2002 to 2003. He was member of the Parti Québécois (PQ), first elected in the 1998 Quebec election in the riding of Rousseau. He was re-elected in 2003, 2007 and 2008 but resigned his seat on June 25, 2009. He returned to the legislature at the 2012 Quebec provincial election as the MNA for L'Assomption, a suburb of Montreal. He was reelected in the 2014 election and won 2018 election. Legault is the first premier not be a member of the Quebec Liberal Party or the Parti Québécois (PQ) since Jean-Jacques Bertrand's 1970 Union Nationale government to.