14 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portageville | 1 | 2,622 | 2,924 | -1.87% | 1,285 | 2 | City |
| New Madrid | 2 | 2,512 | 2,767 | -1.64% | 558 | 5 | City |
| Lilbourn | 3 | 874 | 990 | -2.13% | 924 | 1 | City |
| Gideon | 4 | 689 | 776 | -1.99% | 385 | 2 | City |
| Morehouse | 5 | 658 | 739 | -1.94% | 818 | 1 | City |
| Parma | 6 | 488 | 553 | -2.2% | 765 | 1 | City |
| Matthews | 7 | 485 | 532 | -1.62% | 248 | 2 | City |
| Marston | 8 | 351 | 392 | -1.96% | 318 | 1 | City |
| Risco | 9 | 253 | 283 | -1.94% | 452 | 1 | City |
| Howardville | 10 | 244 | 274 | -2.01% | 1,070 | 0 | City |
| Canalou | 11 | 142 | 157 | -1.39% | 703 | 0 | City |
| Tallapoosa | 12 | 69 | 78 | -1.43% | 155 | 0 | City |
| Catron | 13 | 36 | 38 | 0% | 97 | 0 | Town |
| North Lilbourn | 14 | 19 | 22 | 0% | 110 | 0 | Village |
Portageville is the largest city in New Madrid County, with a population of 2,622.
North Lilbourn is the smallest city in New Madrid County, with a population of 19.
There are 14 cities in New Madrid County, Missouri.