Buying a home in Union County, Illinois doesn't have to be difficult - Homes.com makes home buying a breeze. With 217 homes for sale in Union County, Illinois, you can search by price, bedrooms, neighborhood, and even by property type. Search Union County homes for sale, foreclosures, MLS listings, and more. Make an informed decision with Union County school data, neighborhood information, find Union County real estate agents, and research home values in Union County, IL. Homes.com has everything you need but the house keys.