The river Simme is a tributary of the river Kander in the Bernese Oberland in the canton of Bern in Switzerland. It is approximately 60 kilometres (37 mi) long and has a catchment area of 594 square kilometres (229 sq mi).
The river Simme's spring is on the Rezli alp to the west of the mountain Wildstrubel near the village of Lenk. Underneath the Rezli alp it forms the Simmenfälle, several waterfalls, which have, altogether, a drop of 200 metres (660 ft). Then the river passes Lenk and flows towards Zweisimmen, where it flows together with the Kleine Simme (Little Simme), which flows down from the Saanemöser mountains. It is approximately 10 kilometres (6 mi) long.