Resident Population in Tazewell County, IL was 129.54100 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Tazewell County, IL reached a record high of 136.29700 in January of 2013 and a record low of 118.64900 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Tazewell County, IL - last updated from the United States Federal Reserve on May of 2024.