Lac Martignac is a Lake located in La Tuque; Le Haut-Saint-Maurice, Quebec.

• Latitude: 47° 59' 52'' North   (decimal: 47.9977778)
• Longitude: 75° 7' 39'' West   (decimal: -75.1274999)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: La Tuque; Le Haut-Saint-Maurice
• GPS Coordinate Locator Map: Lac Martignac Lat/Long