Resident Population in Richland County, SC was 425.13800 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Richland County, SC reached a record high of 425.13800 in January of 2023 and a record low of 233.86800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Richland County, SC - last updated from the United States Federal Reserve on May of 2024.