Mexborough is a town in Doncaster, South Yorkshire, England, between Manvers and Denaby Main, on the River Don close to where it joins t…Mexborough is a town in Doncaster, South Yorkshire, England, between Manvers and Denaby Main, on the River Don close to where it joins the River Dearne, and the A6023 road. It is contiguous with Swinton to the southwest and Conisbrough to the east.