9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Munising | 1 | 2,735 | 2,874 | -0.83% | 14 | 202 | Township |
| Munising | 2 | 1,936 | 1,972 | -0.31% | 368 | 5 | City |
| Rock River | 3 | 1,225 | 1,242 | -0.33% | 15 | 81 | Township |
| Au Train | 4 | 1,009 | 1,023 | -0.3% | 7 | 141 | Township |
| Mathias | 5 | 523 | 531 | -0.38% | 7 | 71 | Township |
| Limestone | 6 | 383 | 389 | -0.52% | 5 | 74 | Township |
| Onota | 7 | 367 | 370 | -0.27% | 4 | 88 | Township |
| Chatham | 8 | 213 | 218 | -0.47% | 87 | 2 | Village |
| Grand Island | 9 | 31 | 31 | 0% | 1 | 22 | Township |
Munising is the largest city in Alger County, with a population of 2,735.
Grand Island is the smallest city in Alger County, with a population of 31.
There are 9 cities in Alger County, Michigan.