Resident Population in Hardin County, OH was 30.36800 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Hardin County, OH reached a record high of 32.71900 in January of 1980 and a record low of 30.36800 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Hardin County, OH - last updated from the United States Federal Reserve on May of 2024.