The graph below ranks each Montana County by total residents according to the 2012 census estimates.
Montana total population by county
| County | Total Population |
| Yellowstone |  151,907 |
| Missoula | 111,103 |
| Gallatin | 92,665 |
| Flathead | 91,660 |
| Cascade | 81,784 |
| Lewis and Clark | 64,878 |
| Ravalli | 40,626 |
| Silver Bow | 34,468 |
| Lake | 29,025 |
| Lincoln | 19,504 |
| Hill | 16,410 |
| Park | 15,592 |
| Glacier | 13,643 |
| Big Horn | 12,958 |
| Custer | 11,867 |
| Fergus | 11,448 |
| Jefferson | 11,431 |
| Sanders | 11,392 |
| Roosevelt | 10,903 |
| Richland | 10,817 |
| Carbon | 10,119 |
| Rosebud | 9,405 |
| Beaverhead | 9,375 |
| Dawson | 9,263 |
| Deer Lodge | 9,257 |
| Stillwater | 9,196 |
| Madison | 7,745 |
| Valley | 7,504 |
| Powell | 7,082 |
| Blaine | 6,657 |
| Pondera | 6,155 |
| Teton | 6,051 |
| Chouteau | 5,921 |
| Broadwater | 5,769 |
| Toole | 5,224 |
| Musselshell | 4,674 |
| Mineral | 4,163 |
| Phillips | 4,130 |
| Sweet Grass | 3,600 |
| Sheridan | 3,576 |
| Granite | 3,110 |
| Fallon | 3,039 |
| Liberty | 2,398 |
| Wheatland | 2,100 |
| Judith Basin | 2,029 |
| Meagher | 1,912 |
| Daniels | 1,777 |
| Powder River | 1,760 |
| McCone | 1,692 |
| Garfield | 1,263 |
| Carter | 1,172 |
| Prairie | 1,157 |
| Wibaux | 1,056 |
| Golden Valley | 840 |
| Treasure | 733 |
| Petroleum | 509 |