| Lac Cornu | |
| Pushpin Map: | France |
| Location: | Chamonix-Mont-Blanc, Haute-Savoie |
| Basin Countries: | France |
| Length: | 410m (1,350feet) |
| Width: | 340m (1,120feet) |
| Area: | 5.4ha |
| Max-Depth: | 22m (72feet) |
| Residence Time: | 250 days |
| Elevation: | 2276m (7,467feet) |
Lac Cornu is a lake in the Aiguilles Rouges massif of Haute-Savoie, France. It is located at an elevation of 2,276 m with a surface area of 5.4 ha.
Petit Lac Cornu is located 500 m North West, at an elevation of 2,243 m. Its surface area is 4,700 m².