Sullivan is a village in Jefferson County, Wisconsin, United States. The population was 688 at the 2000 census. The village is located within the Town of Sullivan, and is known to residents of the Milwaukee metro area as the site of the official reporting/warning station of the National Weather Service for southeast Wisconsin. Sullivan apartments for rent comparison page shows most up to date rent information on Sullivan apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.