| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| South Bend | 1 | 103,218 | 103,341 | 0.02% | 2,464 | 42 | City |
| Mishawaka | 2 | 51,189 | 51,052 | -0.07% | 2,810 | 18 | City |
| Osceola | 3 | 2,587 | 2,586 | 0.04% | 1,916 | 1 | Town |
| Walkerton | 4 | 2,071 | 2,096 | -0.14% | 1,089 | 2 | Town |
| New Carlisle | 5 | 1,885 | 1,897 | 0.05% | 929 | 2 | Town |
| North Liberty | 6 | 1,624 | 1,625 | 0% | 1,580 | 1 | Town |
| Lakeville | 7 | 873 | 873 | 0% | 1,395 | 1 | Town |
| Roseland | 8 | 850 | 850 | 0% | 2,255 | 0 | Town |
| Indian Village | 9 | 117 | 117 | 0% | 1,300 | 0 | Town |
South Bend is the largest city in St. Joseph County, with a population of 103,218.
Indian Village is the smallest city in St. Joseph County, with a population of 117.
There are 9 cities in St. Joseph County, Indiana.