The Parti PRO des Lavallois, formerly known as the Parti Ralliement Officiel des Lavallois (PRO Laval), is a defunct municipal political party in Laval, Quebec. It was formerly led by Gilles Vaillancourt, the city's mayor from 1989 to 2012.
The Parti PRO was founded in the early 1980s by a group of councillors who resigned from the city's governing alliance. It was originally progressive but later shifted to a more pro-business position. Party co-founder Ronald Bussey resigned from the group in 1984, charging that it had become dominated by businessmen and former opponents.
The Parti PRO, the dominant municipal party in Laval for several years, has won every council seat in each municipal election since 2001.
Following Vaillancourt's resignation as a result of corruption allegations made at the provincial Charbonneau Commission, the party voted to dissolve on November 19, 2012. Its councillors continued to sit as independents until the following election in november 2013. Only one of them has been reelected, Jacques St-Jean, in the district of St-François.