Resident Population in Osage County, KS was 15.82400 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Osage County, KS reached a record high of 16.73600 in January of 2000 and a record low of 13.35200 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Osage County, KS - last updated from the United States Federal Reserve on May of 2024.