The Voglajna (pronounced [ʋɔˈɡlaːi̯na]) is a river in Styria, Slovenia. The river is 35 kilometres (22 mi) long (including its source river, the Ločnica), and its catchment area is 412 km (159 sq mi). Its source is Lake Slivnica (Slovene: Slivniško jezero) near Slivnica pri Celju. It passes Šentjur, the ruins of Rifnik Castle, and Štore, and then merges with the Savinja River in Celje.

• List of rivers of Slovenia

• Condition of Voglajna - graphs, in the following order, of water level, flow and temperature data for the past 30 days (taken in Črnolica by ARSO)