8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| St. Anthony | 1 | 4,189 | 3,707 | 2.35% | 2,176 | 2 | City |
| Ashton | 2 | 982 | 979 | 0% | 1,539 | 1 | City |
| Teton | 3 | 864 | 791 | 1.65% | 1,254 | 1 | City |
| Newdale | 4 | 332 | 331 | 0% | 1,804 | 0 | City |
| Parker | 5 | 297 | 301 | -0.34% | 856 | 0 | City |
| Island Park | 6 | 190 | 192 | -0.52% | 31 | 6 | City |
| Drummond | 7 | 15 | 14 | 0% | 156 | 0 | City |
| Warm River | 8 | 1 | 1 | 0% | 2 | 1 | City |
St. Anthony is the largest city in Fremont County, with a population of 4,189.
Warm River is the smallest city in Fremont County, with a population of 1.
There are 8 cities in Fremont County, Idaho.