Hillside is a village in Cook County, Illinois, United States. The population was 8,155 at the 2000 census. One notable landmark in Hillside is the Mount Carmel Cemetery. On the grounds of the cemetery are the graves of a number of organized crime figures, such as Al Capone and Dion O'Bannion. A number of Bishops and Archbishops of the Archdiocese of Chicago are buried in the Bishop's Mausoleum at Mount Carmel Cemetery.