Route 125 is a Quebec highway running from Montreal (on Pie-IX Boulevard near the Olympic Stadium) to Saint-Donat, Lanaudière, Quebec in the Lanaudière. The southern section of Route 125 runs parallel to Autoroute 25 in Laval, Mascouche, and Terrebonne. At Saint-Esprit, the Autoroute ends, and 125 continues northwards until the entrance to the Mont Tremblant Provincial Park north of Saint-Donat.