[4] 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.

Near the Port of Waterford it meets the River Barrow at Cheekpoint to form a wide navigable estuary, capable of accommodating seagoing vessels up to 32,000 tons dwt.

[citation needed] Edmund Spenser (1552–1599) author of The Fairie Queene, 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 at Woodstown just upstream from Waterford.

The Office of Public Works (OPW) now plan to install a 1–200-year flood defence where the river Suir flows through Waterford city.