Lac Sunday is a Lake located in Saints-Martyrs-Canadiens; Arthabaska, Quebec and has an elevation of 406 meters.

• Latitude: 45° 52' 50'' North   (decimal: 45.8805916)
• Longitude: 71° 30' 28'' West   (decimal: -71.5078698)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Elevation: 406 meters
• Location: Saints-Martyrs-Canadiens; Arthabaska
• Atlas of Canada Locator Map: Lac Sunday
• GPS Coordinate Locator Map: Lac Sunday Lat/Long