Lac du Soir is a Lake located in Mont-Valin; Le Fjord-du-Saguenay, Quebec.

• Latitude: 48° 39' 22'' North   (decimal: 48.6561111)
• Longitude: 70° 28' 41'' West   (decimal: -70.4780556)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Mont-Valin; Le Fjord-du-Saguenay
• Atlas of Canada Locator Map: Lac du Soir
• GPS Coordinate Locator Map: Lac du Soir Lat/Long