The River Suir (ʃuːr, Irish An tSiúr or Abhainn na Siúire) is a river in Ireland that flows into the Atlantic Ocean near Waterford after a distance of 184 kilometres (114 miles). Popular with anglers, it holds plentiful reserves of brown trout and salmon.
Rising on the slopes of Devil's Bit Mountain, just north of Templemore in County Tipperary, the Suir flows south through Loughmore, Thurles, Holycross, Golden and Knockgraffon. Merging with the River Aherlow at Kilmoyler and further on with the Tar, it turns east at the Comeragh Mountains, forming the border between County Waterford and County Kilkenny. It then passes through Cahir, Clonmel and Carrick-on-Suir before reaching Waterford. Here, it meets the River Barrow and the River Nore to form a wide navigable estuary, capable of accommodating seagoing vessels.
Together with the Nore and the Barrow, the river is one of the trio known as The Three Sisters.
The Suir is known in Irish as the Siúr and it is thought the present spelling in English with the u and i reversed is due to a mistake. Some people therefore feel that the spelling in English should be Siur and this spelling is occasionally seen.. Edmund Spenser (1552-1599), author of the The Fairie Queene and advocate of genocide in Ireland, in his writings during the Elizabethan age while domiciled in County Cork, referred to the 'gentle Shure', probable a most accurate spelling and the most phonetically correct of the period.
In the early years of the 21st century, the remains of a very large Viking settlement were found at a bend in the river just upstream from Waterford.
In Clonmel, the Suir floods the local area after very heavy rainfalls. The Gashouse Bridge (Old Waterford Rd), Coleville Road (Co Waterford), Coleville Avenue, Davis Rd (Waterford Road), Quay's and the Old Bridge are the most commonly affected areas. Clonmel, is not tidal. The tide turns above Meloko in Carrick-on-Suir. The flood water spill on to the land above Meloko on the County Waterford side of the river.
Where the river flows through south County Kilkenny, and near the town of Mooncoin, one of the most famous Irish ballads was written called The Rose of Mooncoin which includes the lines "On the banks of the Suir, that flows down by Mooncoin".