Lac Lost is a Lake located in Notre-Dame-de-Bon-Secours-Partie-Nord; Papineau, Quebec.

• Latitude: 45° 46' 45'' North   (decimal: 45.7792148)
• Longitude: 74° 51' 39'' West   (decimal: -74.8607468)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Notre-Dame-de-Bon-Secours-Partie-Nord; Papineau
• Atlas of Canada Locator Map: Lac Lost
• GPS Coordinate Locator Map: Lac Lost Lat/Long