Dungarvan is a coastal town and harbour in County Waterford, on the south coast of Ireland. Prior to the merger of Waterford County Council with Waterford City Council in 2014, Dungarvan was the county town and administrative centre of County Waterford. Waterford City and County Council retains administrative offices in the town. The town's Irish name means "Garbhan's fort", referring to Saint Garbhan who founded a church there in the seventh century. The town lies on the N25 road (European route E30), which connects Cork, Waterford and Rosslare Europort.
Dungarvan is situated at the mouth of the Colligan River, which divides the town into two parts. Dungarvan to the west, and Abbeyside to the east are connected in three places including a causeway and single-span bridge built by the Dukes of Devonshire starting 1801. A friary in Abbeyside, founded by Augustinians in the 13th century, is partially incorporated with the structure of a 20th-century Roman Catholic church. One of the most significant colleges in the town was also founded by these Augustinians whose order survives and maintains an Augustinian church nearer to the Main Street.
In everyday local usage, "Dungarvan" is taken to refer to the western, less suburban half of the town, where the administrative buildings and shopping areas are situated. A castle, commissioned around the 12th-13th centuries by King John of England, stands by the harbour. But no trace of the walls John built remain.