Dungarvan is a town and harbour on the south coast of Ireland in the province of Munster. Dungarvan is the administrative centre of County Waterford. The town's Irish name means "Garbhan's fort", referring to Saint Garbhan who founded a church there in the seventh century.
Dungarvan is situated at the mouth of the Colligan River which divides the town into two parts connected by a causeway and bridge of a single arch. Both bridge and causeway were built by the Dukes of Devonshire. The town is separated from the open ocean by a shallow, eastward-facing bay. At its mouth, the bay is about two miles wide, with Dungarvan lying about four miles from the mouth.  In Dungarvan proper, a castle built by King John of England stands by the harbour. Of the walls John built at the same time to fortify the town, no trace remain.
Until 1967 Dungarvan had a railway station on the Great Southern & Western Railway route from Mallow in County Cork to Waterford, which saw daily "Boat Express" trains between Cork and Rosslare Harbour. See history of rail transport in Ireland.
A meandering navigation channel marked by red/green buoys leads into Dungarvan from the ocean. For most vessels (except small dingies) this channel is not navigable at low tide. Even at high tide, cruising yachts and larger vessels must be careful to remain in the buoyed channel. There is a well-maintained concrete slipway in Dungarvan town, suitable for launching vessels up to eight metres in length. However, larger vessels should only use it up to three hours either side of high tide. Moorings are usually made available to visiting yachts by Dungarvan Harbour Sailing Club, often free of charge.