Resident Population in St. Lucie County, FL was 373.58600 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in St. Lucie County, FL reached a record high of 373.58600 in January of 2023 and a record low of 50.83600 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in St. Lucie County, FL - last updated from the United States Federal Reserve on May of 2024.