DuPage County (/ˌduːˈpeɪdʒ/) is a county in the U.S. state of Illinois. As of the 2020 census, the population was 932,877,[1] making it Illinois' second-most populous county. Its county seat is Wheaton.[2]
DuPage County has become mostly developed and suburbanized. Residents of Hinsdale, Naperville, and Oak Brook include some of the richest people in the Midwest, and in 2010, Midwest Living voted Hinsdale the Midwest's second-richest town.[3]