County Kilkenny is a county in Ireland. It is in the province of Leinster and is part of the Southern Region. It is named after the city of Kilkenny. …County Kilkenny is a county in Ireland. It is in the province of Leinster and is part of the Southern Region. It is named after the city of Kilkenny. Kilkenny County Council is the local authority for the county. At the 2022 census the population of the county was 103,685. The county was based on the historic Gaelic kingdom of Ossory, which was coterminous with the Diocese of Ossory.