Brookfield (formerly Grossdale) is a suburb of Chicago in Cook County, Illinois, 13 miles (21 km) west of downtown. The population was 19,085 at the 2000 census. It is home to the world-famous Brookfield Zoo.
According to the United States Census Bureau, the village has a total area of 3.1 square miles (7.9 km²), all of it land.
Most of brookfield is flat land with various small hills and rises. Along Salt Creek is a steep ravine that is home to many oak savannas. These oak savannas are the primary ecosystem of Brookfield, and sprawl out from large, forested areas into small pockets in the village.