19 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Plattsmouth | 1 | 7,032 | 6,597 | 1.05% | 2,121 | 3 | City |
| Union | 2 | 2,111 | 1,954 | 0.96% | 80 | 26 | Township |
| Louisville | 3 | 1,423 | 1,335 | 1.07% | 2,137 | 1 | City |
| Eagle | 4 | 1,263 | 1,088 | 2.35% | 2,972 | 0 | Village |
| Weeping Water | 5 | 1,070 | 1,039 | 0.47% | 1,022 | 1 | City |
| Elmwood | 6 | 694 | 669 | 0.58% | 1,539 | 0 | Village |
| Greenwood | 7 | 617 | 595 | 0.65% | 1,501 | 0 | Village |
| Murray | 8 | 505 | 486 | 0.6% | 1,443 | 0 | Village |
| Cedar Creek | 9 | 478 | 463 | 0.63% | 912 | 1 | Village |
| Murdock | 10 | 276 | 269 | 0.36% | 2,015 | 0 | Village |
| Union | 11 | 244 | 245 | 0.83% | 5 | 48 | Township |
| Union | 12 | 205 | 207 | -0.49% | 6 | 36 | Township |
| Union | 13 | 204 | 195 | 0.99% | 1,079 | 0 | Village |
| Avoca | 14 | 182 | 178 | 0.55% | 1,291 | 0 | Village |
| Manley | 15 | 175 | 169 | 0.57% | 1,522 | 0 | Village |
| Nehawka | 16 | 175 | 169 | 0.57% | 714 | 0 | Village |
| Alvo | 17 | 118 | 117 | 0% | 861 | 0 | Village |
| South Bend | 18 | 95 | 89 | 1.06% | 1,284 | 0 | Village |
| Union | 19 | 72 | 74 | -1.37% | 2 | 35 | Township |
Plattsmouth is the largest city in Cass County, with a population of 7,032.
Union is the smallest city in Cass County, with a population of 72.
There are 19 cities in Cass County, Nebraska.