| Helenesee | |
| Pushpin Map: | Brandenburg |
| Location: | Brandenburg |
| Coords: | 52.2711°N 14.4875°W |
| Type: | artificial lake |
| Basin Countries: | Germany |
| Length: | ca. 2.5km (01.6miles) |
| Width: | 0.9km (00.6miles) |
| Area: | ca. 250ha |
| Max-Depth: | 56.63m (185.79feet) |
Helenesee is a lake in Brandenburg, Germany. Its surface area is ca. 250 ha. With a depth of 56.63 m, the Helenseee is the second deepest lake in Brandenburg, only surpassed by the lake Großer Stechlinsee. It is situated approximately 8 kilometers in the south of Frankfurt (Oder). It was formed after the flooding of a former open-pit mining which started in 1958.