15 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sioux City | 1 | 87,368 | 85,888 | 0.28% | 1,471 | 59 | City |
| Sergeant Bluff | 2 | 5,497 | 5,010 | 1.5% | 1,850 | 3 | City |
| Moville | 3 | 1,714 | 1,693 | 0.23% | 1,867 | 1 | City |
| Sloan | 4 | 1,092 | 1,049 | 0.65% | 1,889 | 1 | City |
| Lawton | 5 | 951 | 944 | 0.11% | 1,321 | 1 | City |
| Correctionville | 6 | 758 | 760 | 0% | 1,261 | 1 | City |
| Anthon | 7 | 531 | 539 | -0.19% | 753 | 1 | City |
| Pierson | 8 | 332 | 340 | -0.3% | 699 | 0 | City |
| Danbury | 9 | 313 | 319 | -0.32% | 773 | 0 | City |
| Salix | 10 | 304 | 300 | 0.33% | 179 | 2 | City |
| Bronson | 11 | 293 | 296 | 0% | 847 | 0 | City |
| Hornick | 12 | 254 | 257 | 0% | 827 | 0 | City |
| Cushing | 13 | 222 | 230 | -0.45% | 698 | 0 | City |
| Smithland | 14 | 183 | 186 | 0% | 570 | 0 | City |
| Oto | 15 | 70 | 72 | 0% | 260 | 0 | City |
Sioux City is the largest city in Woodbury County, with a population of 87,368.
Oto is the smallest city in Woodbury County, with a population of 70.
There are 15 cities in Woodbury County, Iowa.