The city of Union is the county seat of Union County, South Carolina, United States. The population was 8,393 at the 2010 census. It is the principal city of the Union Micropolitan Statistical Area, which includes all of Union County and which is further included in the greater Greenville-Spartanburg-Anderson, South Carolina Combined Statistical Area.

Union County is a county located in the U.S. state of South Carolina. As of the 2020 census, the population was 27,244. Its county seat is Union. The county was created in 1785.