19 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Plattsmouth | 1 | 6,959 | 6,597 | 1.05% | 2,099 | 3 | City |
| Union | 2 | 2,091 | 1,954 | 0.97% | 80 | 26 | Township |
| Louisville | 3 | 1,408 | 1,335 | 1% | 2,114 | 1 | City |
| Eagle | 4 | 1,234 | 1,088 | 2.41% | 2,904 | 0 | Village |
| Weeping Water | 5 | 1,065 | 1,039 | 0.47% | 1,017 | 1 | City |
| Elmwood | 6 | 690 | 669 | 0.58% | 1,530 | 0 | Village |
| Greenwood | 7 | 613 | 595 | 0.49% | 1,491 | 0 | Village |
| Murray | 8 | 502 | 486 | 0.6% | 1,434 | 0 | Village |
| Cedar Creek | 9 | 475 | 463 | 0.42% | 906 | 1 | Village |
| Murdock | 10 | 275 | 269 | 0.36% | 2,007 | 0 | Village |
| Union | 11 | 242 | 245 | 0.83% | 5 | 48 | Township |
| Union | 12 | 206 | 207 | -0.48% | 6 | 36 | Township |
| Union | 13 | 202 | 195 | 0.5% | 1,069 | 0 | Village |
| Avoca | 14 | 181 | 178 | 0% | 1,284 | 0 | Village |
| Manley | 15 | 174 | 169 | 0.58% | 1,513 | 0 | Village |
| Nehawka | 16 | 174 | 169 | 0.58% | 710 | 0 | Village |
| Alvo | 17 | 118 | 117 | 0% | 861 | 0 | Village |
| South Bend | 18 | 94 | 89 | 1.08% | 1,270 | 0 | Village |
| Union | 19 | 73 | 74 | -1.35% | 2 | 35 | Township |
Plattsmouth is the largest city in Cass County, with a population of 6,959.
Union is the smallest city in Cass County, with a population of 73.
There are 19 cities in Cass County, Nebraska.