Savannah is a city and county seat of Andrew County, Missouri, United States. The population was 5,069 at the 2020 census. Savannah wa…Savannah is a city and county seat of Andrew County, Missouri, United States. The population was 5,069 at the 2020 census. Savannah was founded in 1841. The city was named after Savannah Woods, the child of a first settler. A post office called Savannah has been in operation since 1841.