Lac Demi-Lune is a Lake located in Lac-Nilgaut; Pontiac, Quebec.

• Latitude: 46° 34' 46'' North   (decimal: 46.5795026)
• Longitude: 77° 12' 3'' West   (decimal: -77.2008411)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Lac-Nilgaut; Pontiac
• Atlas of Canada Locator Map: Lac Demi-Lune
• GPS Coordinate Locator Map: Lac Demi-Lune Lat/Long