Resident Population in Rockcastle County, KY was 16.22600 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Rockcastle County, KY reached a record high of 17.11300 in January of 2011 and a record low of 12.30500 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Rockcastle County, KY - last updated from the United States Federal Reserve on April of 2026.