| Oulankajoki | |
| Mouth: | Lake Pyaozero |
| Mouth Coordinates: | 66.1498°N 30.6116°W |
| Progression: | Lake Pyaozero→ |
| Subdivision Type1: | Countries |
| Length: | ca. 135 km |
| Basin Size: | 5670km2 |
| Tributaries Right: | Kitkajoki |
The Oulankajoki (Russian: Оланга - Olanga) is a river of Finland and Russia (Republic of Karelia). It is part of the Kovda river system. The Oulankajoki discharges into the Lake Pyaozero in the Republic of Karelia in Russia, which is drained by the Kovda towards the White Sea. Its length within Russia is, and it has a drainage basin of .