| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Green Cove Springs | 1 | 10,147 | 9,872 | 0.67% | 1,206 | 8 | City |
| Orange Park | 2 | 8,940 | 9,090 | -0.15% | 2,457 | 4 | Town |
| Keystone Heights | 3 | 1,609 | 1,438 | 1.9% | 1,497 | 1 | City |
| Penney Farms | 4 | 839 | 828 | 0.48% | 575 | 1 | Town |
Green Cove Springs is the largest city in Clay County, with a population of 10,147.
Penney Farms is the smallest city in Clay County, with a population of 839.
There are 4 cities in Clay County, Florida.