| Lake St. Peter | |
| Location: | Ontario, Canada |
| Coordinates: | 45.311°N -78.025°W |
| Type: | lake |
| Pushpin Map: | Ontario |
| Pushpin Map Alt: | Location of the lake in Ontario, Canada. |
Lake St. Peter is a small lake in Ontario in Hastings Highlands, near the village of the same name.
Lake St. Peter Provincial Park is located on Lake St. Peter, 2km (01miles) off Highway 127.