14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Wayne | 1 | 7,963 | 8,039 | 0.49% | 214 | 37 | Township |
| Portland | 2 | 6,208 | 6,333 | -0.4% | 1,274 | 5 | City |
| Dunkirk | 3 | 2,092 | 2,161 | -0.66% | 1,780 | 1 | City |
| Bearcreek | 4 | 1,605 | 1,623 | 0.44% | 44 | 36 | Township |
| Penn | 5 | 1,122 | 1,131 | 0.54% | 37 | 30 | Township |
| Redkey | 6 | 1,070 | 1,095 | -0.47% | 1,228 | 1 | Town |
| Jackson | 7 | 977 | 988 | 0.41% | 27 | 36 | Township |
| Greene | 8 | 942 | 953 | 0.43% | 27 | 35 | Township |
| Pike | 9 | 835 | 842 | 0.72% | 22 | 37 | Township |
| Jefferson | 10 | 687 | 697 | 0.44% | 20 | 35 | Township |
| Pennville | 11 | 614 | 622 | -0.32% | 1,235 | 0 | Town |
| Noble | 12 | 590 | 598 | 0.51% | 19 | 31 | Township |
| Bryant | 13 | 236 | 239 | -0.42% | 740 | 0 | Town |
| Salamonia | 14 | 146 | 150 | -0.68% | 199 | 1 | Town |
Wayne is the largest city in Jay County, with a population of 7,963.
Salamonia is the smallest city in Jay County, with a population of 146.
There are 14 cities in Jay County, Indiana.