St Lucie County is a county located in the U.S. state of Florida. St Lucie County was created in 1844. It was named for Saint Lucie of Syracuse, Roman Catholic saint, born in Sicily, executed in 304 for being a Christian. St.Lucie County is part of the Port St Lucie-Fort Pierce Metropolitan Statistical Area. St Lucie County has a total area of approximately 688 square miles of which 83% is land and 17% water. As of the 2000 census, there were 192,695 people, 76,933 households, and 54,237 families residing in St Lucie County, FL.