Du Page County, IL - Estimate, Median Age by Sex, Total Population (5-year estimate) in DuPage County, IL was 39.90000 Years of Age in January of 2022, according to the United States Federal Reserve. Historically, Du Page County, IL - Estimate, Median Age by Sex, Total Population (5-year estimate) in DuPage County, IL reached a record high of 39.90000 in January of 2022 and a record low of 37.20000 in January of 2009. Trading Economics provides the current actual value, an historical data chart and related indicators for Du Page County, IL - Estimate, Median Age by Sex, Total Population (5-year estimate) in DuPage County, IL - last updated from the United States Federal Reserve on May of 2024.