Diss is a market town and electoral ward in South Norfolk, England, near the boundary with Suffolk, with a population of 7,572 in 2011. Diss railway station is on the Great Eastern Main Line between London and Norwich. It lies in the valley of the River Waveney, round a mere covering 6 acres (2.4 ha) and up to 18 feet (5.5 m) deep, although there is another 51 feet (16 m) of mud.