Lac Gastonguay is a Lake located in Baie-James; Jamésie, Quebec and has an elevation of 391 meters.

• Latitude: 49° 14' 39'' North   (decimal: 49.2441667)
• Longitude: 75° 35' 39'' West   (decimal: -75.5941667)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Elevation: 391 meters
• Location: Baie-James; Jamésie
• Atlas of Canada Locator Map: Lac Gastonguay
• GPS Coordinate Locator Map: Lac Gastonguay Lat/Long