Dungarvan (Irish: Dún Garbháin) is a seaside resort town and harbour on the south coast of Ireland in the province of Munster. Dungarvan is the county town and 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. The town lies on the N25 road (European route E30), which connects Cork, Waterford and Rosslare Europort.

Dungarvan is 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 neighbouring parish is called Abbeyside, where portions of an Augustinian friary founded by the McGraths family in the fourth century survive incorporated with a Roman Catholic church. 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 traces remain.

Dungarvan was incorporated in the 15th century, was represented by two members in the Irish Parliament until the Act of Union in 1801, and returned one member to the Westminster Parliament until 1885. Unlike nearby Waterford and Duncannon, Dungarvan surrendered without a siege in the Cromwellian conquest of Ireland (1649–53).