20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Ontwa | 1 | 6,826 | 6,901 | -0.13% | 352 | 19 | Township |
| Howard | 2 | 6,231 | 6,259 | -0.24% | 180 | 35 | Township |
| Dowagiac | 3 | 5,728 | 5,798 | -0.24% | 1,286 | 4 | City |
| Porter | 4 | 3,945 | 3,753 | 0.41% | 77 | 52 | Township |
| LaGrange | 5 | 3,732 | 3,777 | -0.16% | 112 | 33 | Township |
| Milton | 6 | 3,169 | 3,131 | -0.06% | 150 | 21 | Township |
| Silver Creek | 7 | 3,037 | 3,055 | 0.07% | 95 | 32 | Township |
| Union | 8 | 3,019 | 2,955 | 1.27% | 85 | 35 | Township |
| Jefferson | 9 | 2,557 | 2,588 | -0.31% | 74 | 35 | Township |
| Marcellus | 10 | 2,406 | 2,400 | -0.41% | 72 | 33 | Township |
| Pokagon | 11 | 2,085 | 2,117 | 0.05% | 61 | 34 | Township |
| Calvin | 12 | 2,039 | 1,994 | 1.14% | 59 | 34 | Township |
| Penn | 13 | 1,747 | 1,755 | -0.23% | 52 | 34 | Township |
| Cassopolis | 14 | 1,701 | 1,731 | -0.35% | 846 | 2 | Village |
| Newberg | 15 | 1,582 | 1,608 | -0.57% | 46 | 35 | Township |
| Edwardsburg | 16 | 1,282 | 1,306 | -0.39% | 1,403 | 1 | Village |
| Volinia | 17 | 1,144 | 1,091 | 1.33% | 33 | 34 | Township |
| Marcellus | 18 | 1,041 | 1,076 | -0.67% | 1,526 | 1 | Village |
| Union | 19 | 479 | 471 | 0.42% | 13 | 36 | Township |
| Vandalia | 20 | 320 | 332 | -0.93% | 324 | 1 | Village |
Ontwa is the largest city in Cass County, with a population of 6,826.
Vandalia is the smallest city in Cass County, with a population of 320.
There are 20 cities in Cass County, Michigan.