The River Leven in North Yorkshire, England is a tributary of the River Tees. It rises on Warren Moor, part of Kildale Moor, in the North York Moors and flows to the north of the moors to join the River Tees at Yarm.

North Yorkshire is a ceremonial county in the Yorkshire and the Humber and North East regions of England. It borders County Durham to the north, the North Sea to the east, the East Riding of Yorkshire to the south-east, South Yorkshire to the south, West Yorkshire to the south-west, and Cumbria and Lancashire to the west. Northallerton is the county town.