Hanover Park is a village in Cook and DuPage counties in the U.S. state of Illinois, a suburb of Chicago. The population was 37,973 at the 2010 census. Ontarioville is a neighborhood within the village.
Hanover Park is located at 41°58′44″N 88°8′46″W (41.978827, -88.146109).
According to the 2010 census, Hanover Park has a total area of 6.435 square miles (16.67 km2), of which 6.33 square miles (16.39 km2) (or 98.37%) is land and 0.105 square miles (0.27 km2) (or 1.63%) is water.