| Bjørnsjøen | |
| Location: | Nordmarka, Oslo. |
| Coords: | 60.0667°N 50°W |
| Inflow: | Hakkloelva |
| Pushpin Map: | Norway |
| Outflow: | Bjørnsjøelva |
| Basin Countries: | Norway |
| Area: | 1.7km2 |
| Elevation: | 337m (1,106feet) |
Bjørnsjøen is a lake in Nordmarka in Oslo, Norway. The cabin Kikutstua, owned by the Association for the Promotion of Skiing, is located at the northeastern shore of the lake.[1] Asbjørnsen's story "En Nat i Nordmarken" is set at Bjørnsjøen.[2]
Bjørnsjøen drains through the river Bjørnsjøelva to the lake Skjærsjøen.