Greeneville is a town in Greene County, Tennessee, United States. The population as of the 2010 census was 15,062. It is the county seat of Greene County. The town was named in honor of Revolutionary War hero Nathanael Greene. It is the only town with this spelling in the United States, although there are numerous U.S. towns named Greenville. The town was the capital of the short-lived State of Franklin in the 18th-century history of the Tennessee region.