14 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Wayne | 1 | 8,002 | 8,039 | 0.49% | 215 | 37 | Township |
| Portland | 2 | 6,183 | 6,333 | -0.4% | 1,269 | 5 | City |
| Dunkirk | 3 | 2,078 | 2,161 | -0.67% | 1,769 | 1 | City |
| Bearcreek | 4 | 1,612 | 1,623 | 0.44% | 44 | 36 | Township |
| Penn | 5 | 1,128 | 1,131 | 0.53% | 37 | 30 | Township |
| Redkey | 6 | 1,065 | 1,095 | -0.47% | 1,223 | 1 | Town |
| Jackson | 7 | 981 | 988 | 0.41% | 27 | 36 | Township |
| Greene | 8 | 946 | 953 | 0.42% | 27 | 35 | Township |
| Pike | 9 | 841 | 842 | 0.72% | 23 | 37 | Township |
| Jefferson | 10 | 690 | 697 | 0.44% | 20 | 35 | Township |
| Pennville | 11 | 613 | 622 | -0.16% | 1,233 | 0 | Town |
| Noble | 12 | 593 | 598 | 0.51% | 19 | 31 | Township |
| Bryant | 13 | 236 | 239 | 0% | 740 | 0 | Town |
| Salamonia | 14 | 145 | 150 | -0.68% | 198 | 1 | Town |
Wayne is the largest city in Jay County, with a population of 8,002.
Salamonia is the smallest city in Jay County, with a population of 145.
There are 14 cities in Jay County, Indiana.