| Lac du Lachtelweiher | |
| Pushpin Map: | France |
| Location: | Haut-Rhin |
| Coords: | 47.7772°N 6.9311°W |
| Basin Countries: | France |
| Area: | 0.015km2 |
| Max-Depth: | 5m (16feet) |
| Elevation: | 740m (2,430feet) |
Lac du Lachtelweiher is a lake in Haut-Rhin, France. At an elevation of 740 m, its surface area is 0.015 km². The French name is a tautology as the German Weiher already means pond/lake.