| Lake Atuncocha | |
| Other Name: | Lake Cullicocha |
| Location: | Peru Ancash Region |
| Coords: | -8.8647°N -77.7492°W |
| Length: | 1.88km (01.17miles) |
| Width: | 0.6km (00.4miles) |
| Elevation: | 4625m (15,174feet) |
| Pushpin Map: | Peru |
| Pushpin Map Alt: | Location of the lake in Peru. |
Lake Atuncocha (possibly from Quechua hatun big, large qucha lake, "big lake"), also known as Lake Cullicocha (possibly from Quechua kulli a color between blue and carmine (purple, violet, mulberry-colored) is a lake in Peru located in the Ancash Region, Huaylas Province, Santa Cruz District. It is situated at a height of about 4625m (15,174feet), about 1.88 km long and 0.6 km at its widest point. Lake Atuncocha lies in the Cordillera Blanca, northwest of Santa Cruz and Pergarumi, between Lake Rajucocha in the east and Lake Collorcocha in the west.