Saint-Mathias-sur-Richelieu is a municipality in the Canadian province of Quebec. It is located within the Rouville Regional County Municipality in the Montérégie region on the Richelieu River. The population as of the Canada 2011 Census was 4,618.DemographicsPopulationPopulation trend:LanguageMother tongue language (2006)Notable residentsMichel Jean - Anchorman and journalist TVA Nouvelles and Le Canale Nouvelles (LCN) a Quebec-based news network