The episcopal see has always been in Kilkenny, the capital of Ossory at the time of the Synod of Rathbreasail.

The erroneous belief that the cathedral was originally further north at Aghaboe is traced by John Bradley to a 16th-century misinterpretation of a 13th-century property transfer, combined with the fact that the abbey at the site which became St Canice's Cathedral, Kilkenny, was a daughter house of Aghaboe Abbey.

In the Roman Catholic Church, the title continues as a separate bishopric.

The current Ordinary is the Most Reverend Niall Coll, who was appointed by the Holy See on 28 October 2022 and ordained bishop on 29 December 2022.

[2] Bishops in the early Irish church ruled over a kingdom, in this case, Osraige or Ossory, but were also often associated with a particular monastery and may have been in some matters subordinate to its abbot.