Harmony is an unincorporated community and census-designated place in McHenry County, Illinois, United States. Harmony is located on U.S. Route 20, west-southwest of Huntley. It was named a CDP prior to the 2020 census which showed a population of 20. Demographics 2020 census References Census-designated places in Illinois Census-designated places in McHenry County, Illinois Chicago metropolitan area Unincorporated communities in McHenry County, Illinois Unincorporated communities in Illinois