The central part of County Kilkenny is undulating limestone plain, bordered in some areas by gently sloping hills. Kilkenny City, was home to one of Ireland's most influential Norman families, the Butlers of Ormonde, who founded the town on an existing Irish settlement, at the confluence of the rivers the Barrow, the Nore and the Suir.

It was formerly the Kingdom of Osraige, which existed from at least the 2nd century A.D. until the 13th century. The current Catholic ecclesiastical dioceses of that area is still known as Ossory.

The city of Kilkenny boasts Ireland's most preserved Medieveal town centre, and the Castle and Cathedral which dominate the town are gems of Irish architecture. The county has numerous ancient sites including Iron Age fortifications, inscribed stones and crosses, castles, and abbeys.