Østensjøvannet
| Østensjøvannet Nature Reserve | |
|---|---|
Østensjøvannet lake  | |
| Location | Oslo | 
| Coordinates | 59°53′18″N 10°49′37″E / 59.88833°N 10.82694°E | 
Østensjøvannet (ⓘ) is a lake located in the Østensjø borough in Oslo, Norway. It is well known for the wide variety of birds and other wildlife that can be found there. It is currently a wildlife preserve, though urban development posed a serious threat to the lake and its environs during the 1980s and early 1990s.