Willowbrook is a village in DuPage County, Illinois, United States. The population was 8,967 at the 2000 census.Willowbrook grew from the Ridgemoor subdivision. It was incorporated as a village in 1960.According to the 2010 census, the village has a total area of 2.75 square miles (7.1 km2), of which 2.69 square miles (7.0 km2) (or 97.82%) is land and 0.06 square miles (0.16 km2) (or 2.18%) is water. Willowbrook is around 23 miles (37 km) from Chicago. It is bordered by the suburban villages of Hinsdale, Westmont,Clarendon Hills, Burr Ridge, and Darien, along with unincorporated areas of DuPage County.