Resident Population in Leavenworth County, KS was 83.51800 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Leavenworth County, KS reached a record high of 83.51800 in January of 2023 and a record low of 52.70000 in January of 1971. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Leavenworth County, KS - last updated from the United States Federal Reserve on May of 2024.