7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sanford | 1 | 69,829 | 61,098 | 2.13% | 2,876 | 24 | City |
| Altamonte Springs | 2 | 47,805 | 46,172 | 0.57% | 5,242 | 9 | City |
| Oviedo | 3 | 42,845 | 40,012 | 1.11% | 2,758 | 16 | City |
| Winter Springs | 4 | 40,542 | 38,382 | 0.9% | 2,728 | 15 | City |
| Casselberry | 5 | 33,005 | 28,940 | 2.1% | 4,736 | 7 | City |
| Longwood | 6 | 17,923 | 15,421 | 2.38% | 3,246 | 6 | City |
| Lake Mary | 7 | 17,065 | 16,836 | 0.22% | 1,880 | 9 | City |
Sanford is the largest city in Seminole County, with a population of 69,829.
Lake Mary is the smallest city in Seminole County, with a population of 17,065.
There are 7 cities in Seminole County, Florida.