Saint-Alexis-des-Monts is a parish municipality in the Mauricie region of the province of Quebec in Canada. It is located in the Laurentian Mountains, having a topography that is characterized by valleys and rounded hills, with an altitude varying between 150 metres to 560 metres. There are more than 600 lakes, 400 named and another 200 unnamed minor lakes. The majority of its territory is part of the Matawin Wildlife Reserve.