The Volchya River (Finnish: Saijanjoki (Saejoki, Sadejoki, Suenjoki, Sudenjoki); Russian: Волчья) is a 52 km long tributary of Vuoksi River situated on Karelian Isthmus (Leningrad Oblast, Russia) 0.25-12 km to the west of the Saint Petersburg-Hiitola railroad (along the section between the stations Vaskelovo and Losevo) and flowing northwards from the Lembolovo Heights. Its major tributaries are in turn the Smorodinka (right, Finnish: Tungelmanjoki; Russian: Смородинка), the Belaya (left, Finnish: Valkjoki; Russian: Белая), the Goryunets (left, Russian: Горюнец) and the Petrovka (right, Finnish: Petäjoki, Petojoki, Peto-oja; Russian: Петровка). The Volchya River's width is about 10 m in the lower reaches, where it flows in a narrow valley, with meanders and oxbow lakes.