| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| J and M Trailer Court | city | Montana | United States | 47.15 | -110.22 | 4317 | |
| Jackson | city | Montana | United States | 45.37 | -113.41 | 6709 | |
| Janney | city | Montana | United States | 45.91 | -112.50 | 6043 | |
| Jardine | city | Montana | United States | 45.07 | -110.63 | 7001 | |
| Jeffers | city | Montana | United States | 45.35 | -111.71 | 5029 | |
| Jefferson (historical) | city | Montana | United States | 45.90 | -111.54 | 4189 | |
| Jefferson City | city | Montana | United States | 46.39 | -112.03 | 5029 | |
| Jefferson Island | city | Montana | United States | 45.85 | -111.94 | 4379 | |
| Jellison Place | city | Montana | United States | 46.67 | -110.07 | 6000 | |
| Jennings | city | Montana | United States | 48.37 | -115.34 | 3349 | |
| Jens | city | Montana | United States | 46.60 | -113.01 | 4189 | |
| Jerry Mallo Trailer Court | city | Montana | United States | 46.55 | -110.91 | 5065 | |
| Jessup | city | Montana | United States | 48.21 | -114.13 | 3349 | |
| Jette | city | Montana | United States | 47.72 | -114.19 | 2913 | |
| Jimtown | city | Montana | United States | 45.68 | -106.69 | 3349 | |
| Jitney (historical) | city | Montana | United States | 47.02 | -108.03 | 3349 | |
| Johnson | city | Montana | United States | 45.80 | -112.69 | 6000 | |
| Johnstown (historical) | city | Montana | United States | 47.50 | -111.32 | 3398 | |
| Joliet | city | Montana | United States | 45.49 | -108.97 | 4189 | |
| Joplin | city | Montana | United States | 48.56 | -110.77 | 3349 | |
| Jordan | city | Montana | United States | 47.32 | -106.91 | 2611 | |
| Jordan Crossing | city | Montana | United States | 48.51 | -107.29 | 2509 | |
| Judith (historical) | city | Montana | United States | 47.72 | -109.64 | 2746 | |
| Judith Gap | city | Montana | United States | 46.68 | -109.75 | 4566 | |
| Julian (historical) | city | Montana | United States | 48.94 | -105.36 | 2509 | |
| Junction | city | Montana | United States | 45.32 | -112.00 | 5869 |