| Grand Lac de Laffrey | |
| Location: | Isère |
| Coords: | 45.0111°N 5.7778°W |
| Outflow: | Laffrey |
| Pushpin Map: | France |
| Basin Countries: | France |
| Length: | 3km (02miles) |
| Width: | 0.5km (00.3miles) |
| Area: | 120ha |
| Depth: | 39m (128feet) |
| Elevation: | 911m (2,989feet) |
The Grand lac de Laffrey (pronounced as /fr/, Great Laffrey lake) is the largest of the Laffrey lakes, located in Matheysine 23 km south of Grenoble, in the Isère département of France.