9 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% | 2,136 | 24 | City |
| Lakewood Park | 3 | 14,818 | 14,227 | 1.6% | 2,223 | 7 | CDP |
| Indian River Estates | 4 | 7,151 | 6,542 | 0.87% | 1,288 | 6 | CDP |
| Fort Pierce North | 5 | 6,530 | 7,199 | 0.06% | 1,542 | 4 | CDP |
| River Park | 6 | 6,427 | 7,139 | 1.26% | 2,733 | 2 | CDP |
| White City | 7 | 5,938 | 5,091 | 2.56% | 1,193 | 5 | CDP |
| Fort Pierce South | 8 | 5,377 | 4,468 | 0.39% | 2,074 | 3 | CDP |
| St. Lucie Village | 9 | 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 9 cities in St. Lucie County, Florida.