The River Aln runs through the county of Northumberland in England. It rises in Alnham in the Cheviot Hills and discharges into the North Sea at Alnmouth on the east coast of England. The river gives its name to the town of Alnwick and the villages of Alnmouth and Alnham. For part of its route, directly upstream of Alnwick, the river flows through Hulne Park.