3 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Port St. Lucie | 1 | 271,511 | 206,828 | 5% | 2,277 | 119 | City |
| Fort Pierce | 2 | 51,591 | 47,661 | 1.55% | 2,088 | 25 | City |
| St. Lucie Village | 3 | 616 | 610 | 0.16% | 686 | 1 | Town |
Port St. Lucie is the largest city in St. Lucie County, with a population of 271,511.
St. Lucie Village is the smallest city in St. Lucie County, with a population of 616.
There are 3 cities in St. Lucie County, Florida.