Resident Population in Champaign County, OH was 38.84500 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Champaign County, OH reached a record high of 40.07800 in January of 2010 and a record low of 30.49100 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Champaign County, OH - last updated from the United States Federal Reserve on May of 2024.