The River Dearne is a river in South Yorkshire, England. It flows roughly east for more than thirty kilometres, from its source just inside West Yorkshire, through Denby Dale, Clayton West, Darton, Barnsley, Darfield, Wath upon Dearne and Bolton upon Dearne, to its confluence with the River Don at Conisbrough.

The upper Dearne is followed by the Dearne Way, a footpath through the countryside from Dearne Head to Barnsley. The lower Dearne, the section commonly referred to as the Dearne Valley, was a major coal mining area, but since the closure of the mines, it has become a depressed area, only partially improved by the construction of numerous call centres.

Attractions along the Dearne include the Yorkshire Sculpture Park at Bretton Hall, and Monk Bretton Priory.

The main tributary of the River Dearne is the River Dove.

See also