| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Dubuque | 1 | 58,943 | 59,641 | -0.35% | 1,887 | 31 | City |
| Asbury | 2 | 6,055 | 5,959 | 0.33% | 1,905 | 3 | City |
| Dyersville | 3 | 4,590 | 4,503 | 0.35% | 660 | 7 | City |
| Cascade | 4 | 2,399 | 2,393 | 0% | 1,248 | 2 | City |
| Peosta | 5 | 2,289 | 1,927 | 2.88% | 809 | 3 | City |
| Epworth | 6 | 2,039 | 2,035 | 0.1% | 1,148 | 2 | City |
| Farley | 7 | 1,706 | 1,767 | -0.7% | 1,053 | 2 | City |
| New Vienna | 8 | 380 | 385 | -0.26% | 815 | 0 | City |
| Worthington | 9 | 371 | 379 | -0.54% | 821 | 0 | City |
| Holy Cross | 10 | 341 | 360 | -1.16% | 1,040 | 0 | City |
| Luxemburg | 11 | 234 | 242 | -0.85% | 496 | 0 | City |
| Rickardsville | 12 | 202 | 208 | -0.49% | 220 | 1 | City |
| Sherrill | 13 | 167 | 178 | -1.18% | 1,265 | 0 | City |
| Bernard | 14 | 117 | 115 | 0% | 1,258 | 0 | City |
| Centralia | 15 | 116 | 116 | 0% | 187 | 1 | City |
| Sageville | 16 | 97 | 101 | -1.02% | 115 | 1 | City |
| Zwingle | 17 | 89 | 87 | 0% | 546 | 0 | City |
| Graf | 18 | 75 | 75 | 0% | 564 | 0 | City |
| Bankston | 19 | 27 | 27 | -3.57% | 100 | 0 | City |
| Durango | 20 | 16 | 17 | 0% | 211 | 0 | City |
Dubuque is the largest city in Dubuque County, with a population of 58,943.
Durango is the smallest city in Dubuque County, with a population of 16.
There are 20 cities in Dubuque County, Iowa.