The Oredezh is a river in Volosovsky, Gatchinsky, and Luzhsky Districts in the south-western part of Leningrad Oblast, Russia, a right tributary of the Luga. The length of the river is 192 kilometres (119 mi), whereas the area of its drainage basin is 3,220 square kilometres (1,240 mi2). The principal tributary of the Oredezh is the Suyda (left). A cascade of hydroelectric plants was constructed on the upper course of the river in 1948.