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 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Missouri Valley | 1 | 2,649 | 2,677 | -0.26% | 797 | 3.3 | City |
| Woodbine | 2 | 1,748 | 1,627 | 1.75% | 1,056 | 1.7 | City |
| Logan | 3 | 1,343 | 1,386 | -0.81% | 1,355 | 1.0 | City |
| Dunlap | 4 | 1,033 | 1,041 | -0.19% | 828 | 1.2 | City |
| Mondamin | 5 | 337 | 337 | 0% | 746 | 0.5 | City |
| Persia | 6 | 292 | 296 | -0.34% | 583 | 0.5 | City |
| Modale | 7 | 282 | 274 | 0.71% | 271 | 1.0 | City |
| Pisgah | 8 | 246 | 242 | 0.41% | 492 | 0.5 | City |
| Bentley | 9 | 193 | 158 | 3.21% | 188 | 1.0 | CDP |
| Magnolia | 10 | 188 | 187 | 0% | 308 | 0.6 | City |
| Little Sioux | 11 | 171 | 167 | 0.59% | 456 | 0.4 | City |
| California Junction | 12 | 91 | 40 | 8.33% | 197 | 0.5 | CDP |
| Loveland | 13 | 50 | 0 | 6.38% | 1,282 | 0.0 | CDP |
| River Sioux | 14 | 6 | 40 | 20% | 16 | 0.4 | 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.
Missouri Valley is the largest city in Harrison County.
River Sioux is the smallest city in Harrison County.
There are 14 cities in Harrison County, Iowa.