15 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portageville | 1 | 2,672 | 2,924 | -1.87% | 1,310 | 2 | City |
| New Madrid | 2 | 2,554 | 2,767 | -1.66% | 567 | 5 | City |
| Lilbourn | 3 | 893 | 990 | -2.19% | 944 | 1 | City |
| Gideon | 4 | 703 | 776 | -2.09% | 393 | 2 | City |
| Morehouse | 5 | 671 | 739 | -2.04% | 835 | 1 | City |
| Parma | 6 | 499 | 553 | -2.16% | 782 | 1 | City |
| Matthews | 7 | 493 | 532 | -1.6% | 252 | 2 | City |
| Marston | 8 | 358 | 392 | -1.92% | 324 | 1 | City |
| Risco | 9 | 258 | 283 | -1.9% | 461 | 1 | City |
| Howardville | 10 | 249 | 274 | -1.97% | 1,092 | 0 | City |
| Canalou | 11 | 144 | 157 | -2.04% | 713 | 0 | City |
| Tallapoosa | 12 | 70 | 78 | -2.78% | 157 | 0 | City |
| Catron | 13 | 36 | 38 | -2.7% | 97 | 0 | Town |
| Hayward | 14 | 27 | 79 | -20.59% | 107 | 0 | CDP |
| North Lilbourn | 15 | 19 | 22 | -5% | 110 | 0 | Village |
Portageville is the largest city in New Madrid County, with a population of 2,672.
North Lilbourn is the smallest city in New Madrid County, with a population of 19.
There are 15 cities in New Madrid County, Missouri.