Dadeville is a village in Dade County, Missouri, United States. The population was 226 at the 2020 census. There have been two Dade County towns called Dadeville: an earlier Dadeville was founded in the 1840s and went extinct after the county seat was established at Greenfield. The current site of Dadeville was first called Melville. A po…Dadeville is a village in Dade County, Missouri, United States. The population was 226 at the 2020 census. There have been two Dade County towns called Dadeville: an earlier Dadeville was founded in the 1840s and went extinct after the county seat was established at Greenfield. The current site of Dadeville was first called Melville. A post office called Melville opened in 1853, and the name was changed to Dadeville in 1858. The village is named after Dade County.