Spartanburg is a city in and the seat of Spartanburg County, South Carolina, United States. It is the 12th-largest city by population in the state. The city of Spartanburg has a population of 37,013 as of the 2010 census. The Spartanburg Metropolitan Statistical Area, including Spartanburg and Union counties, had a population of 317,057 as of the 2010-2014 American Community Survey 5-Year Estimates.