Barnsley, town and metropolitan borough, metropolitan county of South Yorkshire, historic county of Yorkshire, northern England. The borough encompasses in addition to Barnsley a number of smaller towns, including Cudworth, Darton, Wombwell, and Penistone, and some open countryside, including a section of the Pennines.

Situated on the River Dearne, a tributary of the Don, Barnsley is an old market town and had early wire-drawing and linen industries, but its major growth came in the 19th century as a coal-mining town in the heart of the Yorkshire coalfield. Local coal production was at its peak at the beginning of the 20th century. As mining employment was subsequently phased out, engineering, clothing, and other light industries were promoted. Barnsley has a mining and technical college and still functions as an agricultural market and service centre. Area metropolitan borough, 127 square miles (329 square km). Pop. (2001) town, 71,599; metropolitan borough, 218,063; (2011) town, 91,297; metropolitan borough, 231,221.