Resident Population in Sumter County, SC was 104.16500 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Sumter County, SC reached a record high of 107.94400 in January of 2012 and a record low of 79.42500 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Sumter County, SC - last updated from the United States Federal Reserve on May of 2024.