14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sanford | 1 | 68,255 | 61,102 | 2.14% | 2,848 | 24 | City |
| Altamonte Springs | 2 | 44,645 | 46,175 | -0.68% | 4,895 | 9 | City |
| Oviedo | 3 | 42,043 | 40,012 | 0.98% | 2,706 | 16 | City |
| Winter Springs | 4 | 39,333 | 38,353 | 0.5% | 2,647 | 15 | City |
| Casselberry | 5 | 31,694 | 28,946 | 1.77% | 4,548 | 7 | City |
| Wekiwa Springs | 6 | 24,838 | 24,008 | 0.77% | 2,892 | 9 | CDP |
| Longwood | 7 | 17,710 | 15,420 | 2.65% | 3,207 | 6 | City |
| Lake Mary | 8 | 16,629 | 16,829 | -0.24% | 1,832 | 9 | City |
| Goldenrod | 9 | 12,610 | 12,341 | 0.3% | 4,996 | 3 | CDP |
| Fern Park | 10 | 8,333 | 8,665 | 0.51% | 4,156 | 2 | CDP |
| Heathrow | 11 | 7,381 | 6,898 | 1.36% | 2,691 | 3 | CDP |
| Geneva | 12 | 3,324 | 3,164 | 0.79% | 261 | 13 | CDP |
| Chuluota | 13 | 2,484 | 1,939 | 0% | 1,216 | 2 | CDP |
| Black Hammock | 14 | 1,139 | 1,080 | 0% | 102 | 11 | CDP |
Sanford is the largest city in Seminole County, with a population of 68,255.
Black Hammock is the smallest city in Seminole County, with a population of 1,139.
There are 14 cities in Seminole County, Florida.