| Iijärvi | |
| Pushpin Map: | Finland |
| Coords: | 65.814°N 29.485°W |
| Lake Type: | Natural |
| Inflow: | Perjakkakoski, Rajajoki, Penikkajoki, Tamppikoski |
| Catchment: | Iijoki |
| Basin Countries: | Finland |
| Area: | 20.537km2 |
| Depth: | 5.09m (16.7feet) |
| Max-Depth: | 20m (70feet) |
| Volume: | 0.105km3 |
| Shore: | 110.08km (68.4miles) |
| Elevation: | 254.1m (833.7feet) |
| Frozen: | November-May |
| Islands: | Kaaperinsaari |
| Cities: | Kuusamo |
Iijärvi is a medium-sized lake in the Iijoki main catchment area. It is located in the Northern Ostrobothnia region. The lake is formed of many long and narrow bays.[1] One of the bays nearly reach the Finnish National Road 5 and there is a hotel on the strand.