Lac Castor is a Lake located in Ferland-et-Boilleau; Le Fjord-du-Saguenay, Quebec.

• Latitude: 48° 10' 17'' North   (decimal: 48.1713889)
• Longitude: 70° 44' 44'' West   (decimal: -70.7455556)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Ferland-et-Boilleau; Le Fjord-du-Saguenay
• Atlas of Canada Locator Map: Lac Castor
• GPS Coordinate Locator Map: Lac Castor Lat/Long