Lac en O is a Lake located in Saint-Just-de-Bretenières; Montmagny, Quebec.

• Latitude: 46° 33' 52'' North   (decimal: 46.5644727)
• Longitude: 70° 4' 32'' West   (decimal: -70.0756235)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Saint-Just-de-Bretenières; Montmagny
• Atlas of Canada Locator Map: Lac en O
• GPS Coordinate Locator Map: Lac en O Lat/Long