Grayslake is a village in Lake County in the U.S. state of Illinois. It is located in the Chicago metropolitan area, about 40 miles (64km) north of Chicagos downtown, 14 miles (23km) west of Lake Michigan, and 15 miles (24km) south of the Wisconsin border. Grayslake is home to the College of Lake County, the University Center of Lake County and the Lake County Fairgrounds. The village's population at the 2000 census was 18,506. As of a special census conducted in 2003, the population was 20,330.