Resident Population in Marlboro County, SC was 25.70400 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Marlboro County, SC reached a record high of 31.82200 in January of 1982 and a record low of 25.70400 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Marlboro County, SC - last updated from the United States Federal Reserve on May of 2024.