Lac Sébast is a Lake located in Rivière-aux-Outardes; Manicouagan, Quebec.

• Latitude: 49° 45' 10'' North   (decimal: 49.7528284)
• Longitude: 69° 7' 36'' West   (decimal: -69.1267561)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Rivière-aux-Outardes; Manicouagan
• Atlas of Canada Locator Map: Lac Sébast
• GPS Coordinate Locator Map: Lac Sébast Lat/Long