Lac des Joncs is a Lake located in Belle-Rivière; Lac-Saint-Jean-Est, Quebec and has an elevation of 370 meters.

• Latitude: 48° 14' 40'' North   (decimal: 48.2444859)
• Longitude: 71° 47' 38'' West   (decimal: -71.7939977)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Elevation: 370 meters
• Location: Belle-Rivière; Lac-Saint-Jean-Est
• Atlas of Canada Locator Map: Lac des Joncs
• GPS Coordinate Locator Map: Lac des Joncs Lat/Long