| Llyn Gwynant | |
| Pushpin Map: | Wales Gwynedd |
| Location: | Snowdonia, Wales |
| Coords: | 53.05°N -6°W |
| Type: | natural |
| Basin Countries: | United Kingdom |
| Area: | 50ha |
Llyn Gwynant is a lake in Snowdonia, Wales.
Llyn Gwynant lies on the River Glaslyn, in the Nant Gwynant valley, and is about 1¼ miles (2 km) north east of Llyn Dinas; the village of Bethania lies between them.
Snowdon lies 2 miles (3 km) to the north west. The lake is natural, having been formed by glacial action and is 120 acres (50 hectares) in size. It is a popular place for canoeing and kayaking with easy access from the A498 road which runs along its south bank.
It was used as a filming location in the 2003 film '', and the 2022 film 'Brian and Charles'.
The view towards Llyn Gwynant and Moel Hebog is one of the most photographed in Snowdonia.