Raška may refer to:
Raška or Old Raška (Стара Рашка) is a region in south-central Serbia, Kosovo and northern Montenegro. In Serbia, the Raška District, Zlatibor District and Moravica District.
In the Middle Ages, the region was a center of the Serbian Principality and of the Serbian Kingdom whose capital was once the city of Ras (a World Heritage Site) until 1265. In the Early Middle Ages, it had parts of present-day southern Serbia, Kosovo, northern Montenegro, eastern Herzegovina. It has given its name to the Raška municipality and town and Raška District.
The Raška is a river in southwestern Serbia, a 60 km-long left tributary to the Ibar river. Its historical name is Arzon ( Greek: Αρζον).
The Raška originates from a strong well and several sinking streams flowing out from the cave south of the Sopoćani monastery, in the Pešter region. Waters of the well and the sinking streams flowing from the Koštan-Polje are gathered into the catchment which enabled construction of the small subterranean hydro electrical power plant Ras (6 MW).
The Raška flows northward during entire of its flow and receives at the village of Pazarište the Sebečevačka reka from the right, between the villages of Dojeviće and Vatevo much longer Ljutska reka from the left and Jošanica from the right at the town of Novi Pazar, the most populous settlement on the river's course.
As it enters the Raška oblast, eastern part of the much larger Stari Vlah-Raška Region of the southwest Serbia, the river flows next to the old Petrova church church and Novi Pazar's suburbs of Banja and Postenje. The lower course is not densely populated, except for the villages of Požežina and Milatkoviće. Finally, the river reaches the town of Raška and its suburb of Supnje, where it empties into the Ibar river.
The Raška drains an area of 1,193 km², belongs to the Black Sea drainage basin and it is not navigable.