Dungarvan, market town, seaport, urban district, and administrative centre of County Waterford, Ireland, on the Bay of Dungarvan at the mouth of the River Colligan. The name is derived from St. Gervan, who founded a monastery there in the 7th century. Ruins include a castle built by King John circa 1200 and a keep and portions of an Augustinian friary. The town has a glue works, a tannery, a dairy-products factory, and a fruit-packing station. Pop. (2002) 7,220; (2010) 7,991.