| Chapfensee | |
|---|---|
| Location | Mels, Canton of St. Gallen |
| Lake type | reservoir |
| Basin countries | Switzerland |
| Water volume | 430,000 m³ |
| Surface elevation | 1030 m |
Chapfensee is a lake at Mels, Canton of St. Gallen, Switzerland. The area around the lake is a nature preserve.
The reservoir was built in 1946/1947 and used to generate power at the plant Plons.