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

• Latitude: 49° 34' 47'' North   (decimal: 49.5797222)
• Longitude: 70° 12' 17'' West   (decimal: -70.2047222)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Mont-Valin; Le Fjord-du-Saguenay
• Atlas of Canada Locator Map: Lac Jonc
• GPS Coordinate Locator Map: Lac Jonc Lat/Long