| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Henry | 1 | 2,270 | 2,340 | -0.44% | 1,263 | 2 | City |
| Lacon | 2 | 1,814 | 1,870 | -0.44% | 1,134 | 2 | City |
| Toluca | 3 | 1,305 | 1,341 | -0.38% | 1,229 | 1 | City |
| Washburn | 4 | 1,003 | 1,033 | -0.5% | 1,389 | 1 | Village |
| Wenona | 5 | 946 | 973 | -0.42% | 1,285 | 1 | City |
| Hopewell | 6 | 410 | 418 | -0.24% | 361 | 1 | Village |
| Varna | 7 | 364 | 371 | -0.27% | 1,226 | 0 | Village |
| Sparland | 8 | 352 | 357 | -0.28% | 615 | 1 | Village |
| La Rose | 9 | 102 | 105 | -0.97% | 400 | 0 | Village |
Henry is the largest city in Marshall County, with a population of 2,270.
La Rose is the smallest city in Marshall County, with a population of 102.
There are 9 cities in Marshall County, Illinois.