| Flatningen | |
| Pushpin Map: | Innlandet#Norway |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location of the lake |
| Coordinates: | 61.7997°N 9.1286°W |
| Location: | Vågå Municipality, Innlandet |
| Basin Countries: | Norway |
| Area: | 2.35km2 |
| Reference: | NVE[1] |
Flatningen is a lake in Vågå Municipality in Innlandet county, Norway. It is located on the far eastern edge of the Jotunheimen mountain range. The 2.35km2 lake lies about south of the village of Vågåmo and about west of the village of Lalm. The lake Lemonsjøen lies about to the southwest of this lake.