Lac Jef is a Lake located in Havre-Saint-Pierre; Minganie, Quebec.

• Latitude: 50° 35' 00'' North   (decimal: 50.5833333)
• Longitude: 63° 37' 47'' West   (decimal: -63.6297222)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Havre-Saint-Pierre; Minganie
• Atlas of Canada Locator Map: Lac Jef
• GPS Coordinate Locator Map: Lac Jef Lat/Long