3 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fernandina Beach | 1 | 13,963 | 13,090 | 1.06% | 1,179 | 12 | City |
| Hilliard | 2 | 3,134 | 2,963 | 0.93% | 569 | 6 | Town |
| Callahan | 3 | 1,909 | 1,537 | 3.36% | 1,056 | 2 | Town |
Fernandina Beach is the largest city in Nassau County, with a population of 13,963.
Callahan is the smallest city in Nassau County, with a population of 1,909.
There are 3 cities in Nassau County, Florida.