| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portageville | 1 | 2,656 | 2,923 | -1.7% | 1,302 | 2 | City |
| New Madrid | 2 | 2,545 | 2,766 | -1.59% | 565 | 5 | City |
| Lilbourn | 3 | 888 | 990 | -1.99% | 939 | 1 | City |
| Gideon | 4 | 695 | 777 | -1.97% | 388 | 2 | City |
| Morehouse | 5 | 668 | 739 | -1.91% | 831 | 1 | City |
| Parma | 6 | 495 | 554 | -2.17% | 776 | 1 | City |
| Matthews | 7 | 485 | 531 | -1.62% | 248 | 2 | City |
| Marston | 8 | 355 | 391 | -1.93% | 321 | 1 | City |
| Risco | 9 | 256 | 284 | -1.92% | 457 | 1 | City |
| Howardville | 10 | 245 | 273 | -2% | 1,075 | 0 | City |
| Canalou | 11 | 142 | 156 | -2.07% | 703 | 0 | City |
| Tallapoosa | 12 | 70 | 78 | -2.78% | 157 | 0 | City |
| Catron | 13 | 36 | 39 | -2.7% | 97 | 0 | Town |
| North Lilbourn | 14 | 21 | 24 | -4.55% | 122 | 0 | Village |
Portageville is the largest city in New Madrid County, with a population of 2,656.
North Lilbourn is the smallest city in New Madrid County, with a population of 21.
There are 14 cities in New Madrid County, Missouri.