11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sidney | 1 | 1,043 | 1,065 | -0.48% | 761 | 1 | City |
| Tabor | 2 | 977 | 1,005 | -0.61% | 756 | 1 | City |
| Hamburg | 3 | 858 | 881 | -0.58% | 765 | 1 | City |
| Farragut | 4 | 478 | 486 | -0.42% | 1,192 | 0 | City |
| Riverton | 5 | 241 | 248 | -0.82% | 400 | 1 | City |
| Randolph | 6 | 181 | 189 | -1.09% | 603 | 0 | City |
| Thurman | 7 | 161 | 163 | -0.62% | 285 | 1 | City |
| Percival | 8 | 130 | 73 | 7.44% | 295 | 0 | CDP |
| Anderson | 9 | 54 | 45 | 8% | 164 | 0 | CDP |
| Imogene | 10 | 36 | 38 | -2.7% | 73 | 0 | City |
| Bartlett | 11 | 15 | 8 | 7.14% | 38 | 0 | CDP |
Sidney is the largest city in Fremont County, with a population of 1,043.
Bartlett is the smallest city in Fremont County, with a population of 15.
There are 11 cities in Fremont County, Iowa.