| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Trumann | 1 | 7,515 | 7,481 | -0.16% | 1,281 | 6 | City |
| Harrisburg | 2 | 2,214 | 2,211 | -0.14% | 913 | 2 | City |
| Marked Tree | 3 | 2,188 | 2,277 | -0.91% | 379 | 6 | City |
| Lepanto | 4 | 1,620 | 1,731 | -1.4% | 1,036 | 2 | City |
| Tyronza | 5 | 711 | 717 | -1.39% | 457 | 2 | City |
| Weiner | 6 | 605 | 646 | -1.31% | 444 | 1 | City |
| Fisher | 7 | 169 | 179 | -1.17% | 567 | 0 | City |
| Waldenburg | 8 | 50 | 54 | -1.96% | 368 | 0 | Town |
Trumann is the largest city in Poinsett County, with a population of 7,515.
Waldenburg is the smallest city in Poinsett County, with a population of 50.
There are 8 cities in Poinsett County, Arkansas.