what county in south carolina is sumter in
Sumter, SC. Sumter ( /sÊmtÉr/) is the county seat of Sumter County, South Carolina, United States. Known as the Sumter Metropolitan Statistical Area, the namesake county adjoins Clarendon and Lee to form the core of Sumter-Lee-Clarendon tri-county area of South Carolina, an area that includes the three counties in east central South Carolina.