7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sanford | 1 | 68,374 | 61,098 | 2.17% | 2,816 | 24 | City |
| Altamonte Springs | 2 | 47,533 | 46,172 | 0.58% | 5,212 | 9 | City |
| Oviedo | 3 | 42,373 | 40,012 | 1.13% | 2,728 | 16 | City |
| Winter Springs | 4 | 40,182 | 38,382 | 0.9% | 2,704 | 15 | City |
| Casselberry | 5 | 32,327 | 28,940 | 2.14% | 4,639 | 7 | City |
| Longwood | 6 | 17,506 | 15,421 | 2.44% | 3,170 | 6 | City |
| Lake Mary | 7 | 17,027 | 16,836 | 0.22% | 1,876 | 9 | City |
Sanford is the largest city in Seminole County, with a population of 68,374.
Lake Mary is the smallest city in Seminole County, with a population of 17,027.
There are 7 cities in Seminole County, Florida.