Kilkenny is a city in Le Sueur County, Minnesota, United States. As of the 2020 census, the population was 148, up from 134 as of the 2010 ce…Kilkenny is a city in Le Sueur County, Minnesota, United States. As of the 2020 census, the population was 148, up from 134 as of the 2010 census. It was twinned with the city and county of Kilkenny in Ireland in 2013.