9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marysville | 1 | 3,409 | 3,448 | -0.18% | 747 | 5 | City |
| Blue Rapids | 2 | 918 | 926 | -0.11% | 462 | 2 | City |
| Frankfort | 3 | 725 | 728 | 0% | 720 | 1 | City |
| Waterville | 4 | 646 | 658 | -0.31% | 1,313 | 0 | City |
| Axtell | 5 | 409 | 397 | 0.49% | 782 | 1 | City |
| Beattie | 6 | 201 | 203 | 0% | 878 | 0 | City |
| Summerfield | 7 | 123 | 126 | 0% | 357 | 0 | City |
| Vermillion | 8 | 75 | 78 | 0% | 361 | 0 | City |
| Oketo | 9 | 61 | 61 | 0% | 592 | 0 | City |
Marysville is the largest city in Marshall County, with a population of 3,409.
Oketo is the smallest city in Marshall County, with a population of 61.
There are 9 cities in Marshall County, Kansas.