Port St. Lucie is a city in St. Lucie County, Florida, United States. It is the most-populous municipality in the county and the sixth-most populous city in Florida, with a population of 204,851 at the 2020 census. It is located 125 miles (201 km) southeast of Orlando and 113 miles (182 km) north of Miami. It is a principal city in the Port St. Lucie metropolitan statistical area, which includes S…