Greendale is a city in Dearborn County, Indiana, United States. The population was 4,602 at the 2020 census, up 82 since the 2010 Cens…Greendale is a city in Dearborn County, Indiana, United States. The population was 4,602 at the 2020 census, up 82 since the 2010 Census. Greendale was laid out in 1852, but the plat was not recorded until 1883. Greendale likely took its name from Greendale Cemetery.