Resident Population in Carroll County, IL was 15.52600 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Carroll County, IL reached a record high of 19.60000 in January of 1975 and a record low of 14.33700 in January of 2018. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Carroll County, IL - last updated from the United States Federal Reserve on May of 2024.