Greenville is the largest city and the county seat of Greenville County in the upstate region of South Carolina, in the United States. The city's mayor is Knox White, who has served in that position since December 1995. With an estimated population of 64,579 as of 2015, it is the sixth-largest city in the state. The population of the surrounding area was 400,492 as of 2010, making it the third-largest urban area in South Carolina as well as the fastest growing.