There are 23 cities in Washington County, Iowa.
Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Population | 2020 Population | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mount Pleasant | 1 | 8,356 | 9,255 | -2.62% | 968 | 8.6 | City |
| Washington | 2 | 7,220 | 7,346 | -0.44% | 1,336 | 5.4 | City |
| Kalona | 3 | 2,772 | 2,638 | 1.21% | 1,286 | 2.2 | City |
| Columbus Junction | 4 | 1,751 | 1,830 | -1.13% | 816 | 2.1 | City |
| Wellman | 5 | 1,513 | 1,523 | -0.2% | 1,411 | 1.1 | City |
| Riverside | 6 | 1,041 | 1,060 | -0.48% | 564 | 1.8 | City |
| Wayland | 7 | 942 | 960 | -0.53% | 885 | 1.1 | City |
| Keota | 8 | 892 | 894 | -0.11% | 1,154 | 0.8 | City |
| Brighton | 9 | 586 | 598 | -0.51% | 749 | 0.8 | City |
| Richland | 10 | 540 | 539 | 0% | 522 | 1.0 | City |
| Ainsworth | 11 | 514 | 508 | 0.19% | 1,393 | 0.4 | City |
| Crawfordsville | 12 | 278 | 277 | 0% | 757 | 0.4 | City |
| Fredonia | 13 | 208 | 219 | -1.42% | 1,377 | 0.2 | City |
| West Chester | 14 | 147 | 145 | 0% | 581 | 0.3 | City |
| Swedesburg | 15 | 126 | 175 | 7.69% | 55 | 2.3 | CDP |
| Rome | 16 | 111 | 114 | -0.89% | 895 | 0.1 | City |
| Westwood | 17 | 98 | 104 | -2% | 899 | 0.1 | City |
| Trenton | 18 | 82 | 94 | 7.9% | 178 | 0.5 | CDP |
| Pleasant Plain | 19 | 79 | 82 | -1.25% | 78 | 1.0 | City |
| Kinross | 20 | 76 | 78 | -1.3% | 402 | 0.2 | City |
| Cotter | 21 | 36 | 38 | -2.7% | 367 | 0.1 | City |
| Coppock | 22 | 35 | 37 | -2.78% | 152 | 0.2 | City |
| Frytown | 23 | 13 | 47 | -45.83% | 16 | 0.8 | CDP |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Mount Pleasant is the largest city in Washington County.
Frytown is the smallest city in Washington County.
There are 23 cities in Washington County, Iowa.