9 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Joliet | Carbon County | 639 |
| Jefferson City | Jefferson County | 440 |
| Jordan | Garfield County | 359 |
| Joplin | Liberty County | 295 |
| Jette | Lake County | 214 |
| Judith Gap | Wheatland County | 107 |
| Jardine | Park County | 78 |
| Jeffers | Madison County | 64 |
| Jackson | Beaverhead County | 28 |