It was a symbol of Norman occupation, and in its original 13th-century condition, it would have formed an important element of the town's defences with four large circular corner towers and a massive ditch, part of which can still be seen today on the Parade.

Since 2002, ceremonies for conferring awards and degrees on the graduates of the Kilkenny Campus of the National University of Ireland, Maynooth, have been held at the castle.

Richard de Clare, 2nd Earl of Pembroke, commonly known as Strongbow constructed the first castle, probably a wooden structure, in the 12th century.

The Anglo-Normans had established a castle in 1173, possibly on the site of an earlier residence of the Mac Giolla Phádraig kings of Osraighe.

[4] In the 17th century, the castle came into the hands of Elizabeth Preston, wife of then Lord Lieutenant of Ireland, James Butler, 1st Duke of Ormond.

The east wall and the northeast tower of the Castle were damaged in 1650 during the siege of Kilkenny by Oliver Cromwell during the Cromwellian conquest of Ireland.

However, some restoration was carried out by Anne Wandesford of Castlecomer, who brought wealth back into the family upon marrying John Butler, 17th Earl of Ormonde.

In the 19th century, the Butlers then attempted to restore it to its original medieval appearance, also rebuilding the north wing and extending the south curtain wall.

In 1904, King Edward VII of the United Kingdom of Great Britain and Ireland and his wife Queen Alexandra visited Kilkenny Castle.

[9] George Butler, Earl of Ossory and his family remained living in the castle until 1935,[2] when they sold its contents for £6,000, moved to London, and abandoned it for thirty years.

The handover ceremony also marked the foundation of The Butler Society,[11] a still thriving organisation that connects, preserves and unites a family once dominant in the British Isles.

[14] The Butler Gallery, previously based in the basement of Kilkenny Castle,[15][16] is located in the redeveloped Evans' Home, a former almshouse built in the 19th century for impoverished domestic servants.

[17][18] It holds rotating exhibitions put on by the Kilkenny Art Gallery Society in a venue named for Peggy and Hubert Butler.