| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Ontwa | 1 | 6,853 | 6,898 | 0.2% | 353 | 19 | Township |
| Howard | 2 | 6,257 | 6,253 | 0.03% | 181 | 35 | Township |
| Dowagiac | 3 | 5,712 | 5,797 | -0.23% | 1,283 | 4 | City |
| Porter | 4 | 3,966 | 3,753 | 0.51% | 77 | 52 | Township |
| LaGrange | 5 | 3,724 | 3,779 | 0% | 112 | 33 | Township |
| Milton | 6 | 3,194 | 3,139 | 0.22% | 151 | 21 | Township |
| Silver Creek | 7 | 3,056 | 3,052 | 0.49% | 96 | 32 | Township |
| Union | 8 | 2,967 | 2,953 | -0.07% | 84 | 35 | Township |
| Jefferson | 9 | 2,599 | 2,589 | 0.7% | 75 | 35 | Township |
| Marcellus | 10 | 2,409 | 2,398 | -0.08% | 73 | 33 | Township |
| Pokagon | 11 | 2,087 | 2,118 | 0.14% | 61 | 34 | Township |
| Calvin | 12 | 2,041 | 1,996 | 0.54% | 59 | 34 | Township |
| Penn | 13 | 1,779 | 1,758 | 0.62% | 53 | 34 | Township |
| Cassopolis | 14 | 1,700 | 1,732 | -0.41% | 845 | 2 | Village |
| Newberg | 15 | 1,608 | 1,607 | 0.63% | 47 | 35 | Township |
| Edwardsburg | 16 | 1,281 | 1,303 | -0.39% | 1,402 | 1 | Village |
| Volinia | 17 | 1,174 | 1,089 | 2% | 34 | 34 | Township |
| Marcellus | 18 | 1,039 | 1,073 | -0.57% | 1,154 | 1 | Village |
| Union | 19 | 485 | 473 | 0.62% | 14 | 36 | Township |
| Vandalia | 20 | 325 | 335 | -0.61% | 329 | 1 | Village |
Ontwa is the largest city in Cass County, with a population of 6,853.
Vandalia is the smallest city in Cass County, with a population of 325.
There are 20 cities in Cass County, Michigan.