| Lake Iijärvi | |
| Pushpin Map: | Finland |
| Coords: | 65.51°N 29.545°W |
| Lake Type: | Natural |
| Inflow: | Sakkojoki |
| Outflow: | Joutenvirta |
| Catchment: | Oulujoki |
| Basin Countries: | Finland |
| Area: | 7.792km2 |
| Depth: | 7.82m (25.66feet) |
| Volume: | 0.0615km3 |
| Shore: | 34.09km (21.18miles) |
| Elevation: | 218.1m (715.6feet) |
| Frozen: | November-May |
Lake Iijärvi (Suomussalmi) is a rather small lake of northern Finland. It belongs to the Oulujoki main catchment area. It is situated partly in Kainuu region and partly in Northern Ostrobothnia region.[1] The lake is situated in the border of Hossa Nature Protection Area.