12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| South Bend | 1 | 103,435 | 103,335 | 0.02% | 2,469 | 41.90 | City |
| Mishawaka | 2 | 50,708 | 51,042 | -0.13% | 2,813 | 18.03 | City |
| Granger | 3 | 29,907 | 30,499 | -0.13% | 1,216 | 24.60 | CDP |
| Notre Dame | 4 | 6,606 | 6,699 | 0.66% | 5,589 | 1.18 | CDP |
| Osceola | 5 | 2,597 | 2,586 | 0.08% | 1,924 | 1.35 | Town |
| Walkerton | 6 | 2,089 | 2,094 | -0.05% | 1,099 | 1.90 | Town |
| New Carlisle | 7 | 1,921 | 1,893 | 0.31% | 947 | 2.03 | Town |
| North Liberty | 8 | 1,625 | 1,625 | 0% | 1,581 | 1.03 | Town |
| Lakeville | 9 | 877 | 874 | 0.11% | 1,401 | 0.63 | Town |
| Roseland | 10 | 851 | 851 | 0% | 2,257 | 0.38 | Town |
| Wyatt | 11 | 221 | 0 | 7.28% | 220 | 1 | CDP |
| Indian Village | 12 | 116 | 118 | 0% | 1,289 | 0.09 | Town |
South Bend is the largest city in St. Joseph County, with a population of 103,435.
Indian Village is the smallest city in St. Joseph County.
There are 12 cities in St. Joseph County, Indiana.