9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Henry | 1 | 2,277 | 2,340 | -0.44% | 1,267 | 2 | City |
| Lacon | 2 | 1,821 | 1,871 | -0.44% | 1,138 | 2 | City |
| Toluca | 3 | 1,310 | 1,342 | -0.38% | 1,234 | 1 | City |
| Washburn | 4 | 1,002 | 1,029 | -0.4% | 1,388 | 1 | Village |
| Wenona | 5 | 947 | 971 | -0.42% | 1,287 | 1 | City |
| Hopewell | 6 | 413 | 419 | -0.24% | 364 | 1 | Village |
| Varna | 7 | 370 | 376 | -0.27% | 1,246 | 0 | Village |
| Sparland | 8 | 353 | 358 | -0.28% | 617 | 1 | Village |
| La Rose | 9 | 97 | 99 | 0% | 380 | 0 | Village |
Henry is the largest city in Marshall County, with a population of 2,277.
La Rose is the smallest city in Marshall County, with a population of 97.
There are 9 cities in Marshall County, Illinois.