The River Lowther is a small river which flows through limestone rock in Cumbria, England. It is a tributary of the River Eamont which in turn is a tributary of the River Eden which flows into the Solway Firth near Carlisle. The Lowther begins with the confluence of the and the near the village of Keld. It flows north-west until it passes between Bampton and Bampton Grange, before turning north until it flows into the River Eamont close to Penrith.