Crest Hill is a city in Lockport Township, Will County, Illinois, United States. The 2010 census put Crest Hill's population at 20,837.
Crest Hill is located at 41°33′52″N 88°6′31″W (41.5645, -88.1089). Crest Hill decided to incorporate itself to avoid being annexed by the City of Joliet and became officially incorporated as the City of Crest Hill January 22, 1960.
According to the 2010 census, Crest Hill has a total area of 9.166 square miles (23.74 km2), of which 9.03 square miles (23.39 km2) (or 98.52%) is land and 0.136 square miles (0.35 km2) (or 1.48%) is water.