| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Port St. Lucie | 1 | 281,097 | 206,788 | 4.86% | 2,358 | 119 | City |
| Fort Pierce | 2 | 52,588 | 47,573 | 1.64% | 2,128 | 25 | City |
| St. Lucie Village | 3 | 644 | 631 | 0.31% | 717 | 1 | Town |
Port St. Lucie is the largest city in St. Lucie County, with a population of 281,097.
St. Lucie Village is the smallest city in St. Lucie County, with a population of 644.
There are 3 cities in St. Lucie County, Florida.