Antioch is a village in Lake County, Illinois, United States. As of the 2020 census, the population was 14,622. The village is nestled into the Ch…Antioch is a village in Lake County, Illinois, United States. As of the 2020 census, the population was 14,622. The village is nestled into the Chain O'Lakes waterway system and borders the state of Wisconsin. Part of the Chicago metropolitan area, Antioch is located approximately halfway between the major cities of Chicago and Milwaukee.