13 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Neosho | 1 | 14,310 | 12,726 | 1.88% | 918 | 16 | City |
| Seneca | 2 | 2,354 | 2,239 | 0.81% | 920 | 3 | City |
| Granby | 3 | 2,121 | 2,048 | 0.57% | 479 | 4 | City |
| Diamond | 4 | 918 | 834 | 1.55% | 1,229 | 1 | Town |
| Fairview | 5 | 796 | 735 | 1.4% | 25 | 31 | Township |
| Fairview | 6 | 435 | 419 | 0.69% | 922 | 0 | Town |
| Fairview | 7 | 418 | 408 | 0.24% | 9 | 46 | Township |
| Saginaw | 8 | 340 | 300 | 2.1% | 412 | 1 | Village |
| Newtonia | 9 | 215 | 208 | 0.47% | 660 | 0 | Town |
| Stella | 10 | 171 | 165 | 0.59% | 1,049 | 0 | Town |
| Fairview | 11 | 161 | 160 | -0.62% | 5 | 36 | Township |
| Stark City | 12 | 131 | 127 | 0.77% | 402 | 0 | Town |
| Ritchey | 13 | 69 | 66 | 1.47% | 1,408 | 0 | Town |
Neosho is the largest city in Newton County, with a population of 14,310.
Ritchey is the smallest city in Newton County, with a population of 69.
There are 13 cities in Newton County, Missouri.