Spartanburg is a city in and the seat of Spartanburg County, South Carolina, United States. The city had a population of 38,732 as of the 2020 census, making it the 11th-most populous city in the state. For a time, the Office of Management and Budget grouped Spartanburg and Union counties together as the Spartanburg, SC Metropolitan Statistical Area, but the OMB now defines the Spartanburg, SC MSA as only Spartanburg County.