| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Frenchtown | 1 | 21,825 | 21,580 | 0.33% | 523 | 42 | Township |
| Monroe | 2 | 20,001 | 20,449 | -0.37% | 2,211 | 9 | City |
| Monroe | 3 | 14,245 | 14,386 | -0.22% | 844 | 17 | Township |
| Woodhaven | 4 | 12,413 | 12,892 | -0.72% | 1,943 | 6 | City |
| Berlin | 5 | 10,206 | 9,900 | 0.82% | 319 | 32 | Township |
| Dundee | 6 | 8,786 | 8,170 | 0.07% | 182 | 48 | Township |
| Ash | 7 | 8,029 | 7,872 | 0.2% | 232 | 35 | Township |
| Raisinville | 8 | 6,175 | 5,940 | 0.64% | 128 | 48 | Township |
| Dundee | 9 | 6,162 | 5,387 | 2.56% | 1,175 | 5 | Village |
| Milan | 10 | 5,954 | 6,070 | -0.32% | 1,712 | 3 | City |
| Ida | 11 | 4,799 | 4,795 | -0.19% | 131 | 37 | Township |
| Whiteford | 12 | 4,607 | 4,614 | -0.24% | 116 | 40 | Township |
| La Salle | 13 | 4,589 | 4,644 | -0.04% | 173 | 27 | Township |
| Erie | 14 | 4,348 | 4,303 | 0% | 182 | 24 | Township |
| Exeter | 15 | 3,981 | 3,934 | 0.1% | 109 | 37 | Township |
| Summerfield | 16 | 3,198 | 3,186 | 0.09% | 76 | 42 | Township |
| London | 17 | 3,016 | 2,986 | 0.33% | 84 | 36 | Township |
| Carleton | 18 | 2,293 | 2,332 | -0.39% | 2,314 | 1 | Village |
| South Rockwood | 19 | 1,572 | 1,594 | -0.25% | 480 | 3 | Village |
| Milan | 20 | 1,533 | 1,561 | -0.45% | 45 | 34 | Township |
| Luna Pier | 21 | 1,345 | 1,377 | -0.44% | 901 | 1 | City |
| Petersburg | 22 | 1,149 | 1,167 | -0.26% | 2,379 | 0 | City |
| Maybee | 23 | 586 | 546 | 1.38% | 318 | 2 | Village |
| Estral Beach | 24 | 412 | 418 | -0.24% | 936 | 0 | Village |
| Monroe | 25 | 344 | 334 | 0.29% | 10 | 36 | Township |
Frenchtown is the largest city in Monroe County, with a population of 21,825.
Monroe is the smallest city in Monroe County, with a population of 344.
There are 25 cities in Monroe County, Michigan.