Resident Population in Neosho County, KS was 15.55200 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Neosho County, KS reached a record high of 19.41500 in January of 1981 and a record low of 15.45100 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Neosho County, KS - last updated from the United States Federal Reserve on April of 2026.