Lac Grand Rosoy is a Lake located in Rivière-Koksoak; Kativik, Quebec.

• Latitude: 55° 27' 52'' North   (decimal: 55.4644444)
• Longitude: 65° 28' 20'' West   (decimal: -65.4722222)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Rivière-Koksoak; Kativik
• Atlas of Canada Locator Map: Lac Grand Rosoy
• GPS Coordinate Locator Map: Lac Grand Rosoy Lat/Long