Charleston is the largest city in the U.S. state of South Carolina, the county seat of Charleston County, and the principal city in the Charleston–North Charleston metropolitan area. The city lies just south of the geographical midpoint of South Carolina’s coastline on Charleston Harbor, an inlet of the Atlantic Ocean formed by the confluence of the Ashley, Cooper, and Wando rivers. Charleston had a population of 150,277 as of the 2020 U.S. Census.The 2020 population of the Charleston metropolitan area, comprising Berkeley, Charleston, and Dorchester counties, was 799,636 residents, the third-largest in the state and the 74th-largest metropolitan statistical area in the United States.

Charleston was founded in 1670 as Charles Town, honoring King Charles II, at Albemarle Point on the west bank of the Ashley River (now Charles Towne Landing) but relocated in 1680 to its present site, which became the fifth-largest city in North America within ten years. It remained unincorporated throughout the colonial period; its government was handled directly by a colonial legislature and a governor sent by Parliament. Election districts were organized according to Anglican parishes, and some social services were managed by Anglican wardens and vestries. Charleston adopted its present spelling with its incorporation as a city in 1783. Population growth in the interior of South Carolina influenced the removal of the state government to Columbia in 1788, but Charleston remained among the ten largest cities in the United States through the 1840 census.