The Oulankajoki is a river of Finland and Russia. 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 67 kilometres (42 mi), and it has a drainage basin of 5,670 square kilometres (2,190 sq mi).