The Paatsjoki River (, , , , , ) is a river that flows through Finland, Norway, and Russia. Since 1826, the river has marked parts of the Norway–Russia border, except from 1920 to 1944 when it was along the Finland–Norway border.

The Paatsjoki River (, , , , , ) is a river that flows through Finland, Norway, and Russia. Since 1826, the river has marked parts of the Norway–Russia border, except from 1920 to 1944 when it was along the Finland–Norway border.