Founded in March 12, 1885, Fergus County is one of 56 counties in the state of Montana. Historically, Fergus County was formed from Chouteau County and Meagher County. The city of Lewistown is the county seat. With FIPS code of 27, Fergus County has a population of 11,617 and area of 4,339 square miles (11,238 km2).
List of all cities in Fergus County, MT alphabetically
| City/Town | Postal Code | Area Code |
| Buffalo, MT | 59418 | 406 |
| Coffee Creek, MT | 59424 | 406 |
| Denton, MT | 59430 | 406 |
| Forest Grove, MT | 59441 | 406 |
| Grass Range, MT | 59032 | 406 |
| Heath, MT | 59457 | 406 |
| Hilger, MT | 59451 | 406 |
| Lewistown, MT | 59457 | 406 |
| Moore, MT | 59464 | 406 |
| Roy, MT | 59471 | 406 |
| Straw, MT | 59418 | 406 |
| Winifred, MT | 59489 | 406 |