The Hudinja (pronounced [xuˈdiːnja]) is a river in Styria, Slovenia. The river is 32 kilometres (20 mi) in length. Its source is on the Pohorje Massif southwest of Mount Rogla, about 1380 m above sea level, near the source of Dravinja River. The river passes Vitanje, Socka Castle, Vojnik, and Celje, where it flows into the Voglajna. A district of Celje also named lies on the river.