Wath upon Dearne is a town south of the River Dearne in the Metropolitan Borough of Rotherham, South Yorkshire, England, 5 miles (8 km) north of Rotherham and almost midway between Barnsley and Doncaster. It had a population of 11,816 at the 2011 census. It is twinned with Saint-Jean-de-Bournay in France.

The River Dearne South Yorkshire, England flows roughly east for more than 30 kilometres (19 mi), from its source just inside West Yorkshire. It flows through Denby Dale, Clayton West, Darton, Barnsley, Darfield, Wath upon Dearne, Bolton on Dearne, Adwick upon Dearne and Mexborough to its confluence with the River Don at Denaby Main. Its main tributary is the River Dove, which joins it at Darfield. The river was one of those affected by the 2007 United Kingdom floods.