| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Munising | 1 | 2,728 | 2,881 | -1.12% | 13 | 202 | Township |
| Munising | 2 | 1,932 | 1,974 | -0.31% | 367 | 5 | City |
| Rock River | 3 | 1,223 | 1,245 | -0.57% | 15 | 81 | Township |
| Au Train | 4 | 1,001 | 1,021 | -0.6% | 7.0 | 141 | Township |
| Mathias | 5 | 526 | 535 | -0.57% | 7.0 | 71 | Township |
| Limestone | 6 | 375 | 382 | -0.79% | 5.0 | 74 | Township |
| Onota | 7 | 367 | 370 | -0.27% | 4.0 | 88 | Township |
| Chatham | 8 | 213 | 217 | -0.47% | 87 | 2 | Village |
| Grand Island | 9 | 31 | 31 | 0% | 1.0 | 22 | Township |
Munising is the largest city in Alger County, with a population of 2,728.
Grand Island is the smallest city in Alger County, with a population of 31.
There are 9 cities in Alger County, Michigan.