The 56 counties in Montana combine for a total population for the state of 1,084,225 (2021 census). There are just 4 counties with a population of over 100,000, these include Yellowstone, Missoula, Gallatin, and Flathead. On the opposite end of the spectrum, we have Wibaux, Golden Valley, Treasure, and Petroleum with fewer than 1,000 people in the entire county!
The data below comes from the 2021 census conducted by the U.S. Census Bureau and is updated frequently to reflect the most recent data possible.
Click here to view the population of cities in Montana.
| County | Population Total (2021) | Population Total (2020) | Change (2020) |
|---|---|---|---|
| Yellowstone | 167,146 | 165,045 | 2,101 |
| Missoula | 119,533 | 118,238 | 1,295 |
| Gallatin | 122,713 | 119,502 | 3,211 |
| Flathead | 108,454 | 104,773 | 3,681 |
| Cascade | 84,511 | 84,328 | 183 |
| Lewis and Clark | 72,223 | 71,093 | 1,130 |
| Ravalli | 45,959 | 44,351 | 1,608 |
| Silver Bow | 35,411 | 35,168 | 243 |
| Lake | 32,033 | 31,259 | 774 |
| Lincoln | 20,525 | 19,731 | 794 |
| Park | 17,473 | 17,193 | 280 |
| Hill | 16,179 | 16,250 | -71 |
| Glacier | 13,785 | 13,747 | 38 |
| Big Horn | 12,957 | 13,051 | -94 |
| Jefferson | 12,470 | 12,133 | 337 |
| Sanders | 12,959 | 12,451 | 508 |
| Custer | 11,916 | 11,859 | 57 |
| Fergus | 11,617 | 11,457 | 160 |
| Richland | 11,283 | 11,501 | -218 |
| Roosevelt | 10,821 | 10,780 | 41 |
| Carbon | 10,847 | 10,512 | 335 |
| Stillwater | 9,044 | 9,010 | 34 |
| Beaverhead | 9,524 | 9,372 | 152 |
| Deer Lodge | 9,491 | 9,413 | 78 |
| Madison | 8,917 | 8,657 | 260 |
| Rosebud | 8,124 | 8,298 | -174 |
| Dawson | 8,904 | 8,922 | -18 |
| Valley | 7,537 | 7,551 | -14 |
| Powell | 6,999 | 6,934 | 65 |
| Blaine | 6,980 | 7,002 | -22 |
| Broadwater | 7,288 | 6,846 | 442 |
| Teton | 6,269 | 6,242 | 27 |
| Pondera | 5,994 | 5,882 | 112 |
| Chouteau | 5,916 | 5,899 | 17 |
| Toole | 5,011 | 4,964 | 47 |
| Musselshell | 4,896 | 4,747 | 149 |
| Mineral | 4,860 | 4,565 | 295 |
| Phillips | 4,192 | 4,190 | 2 |
| Sweet Grass | 3,723 | 3,671 | 52 |
| Granite | 3,344 | 3,308 | 36 |
| Sheridan | 3,527 | 3,518 | 9 |
| Fallon | 3,017 | 3,033 | -16 |
| Liberty | 1,946 | 1,960 | -14 |
| Wheatland | 2,059 | 2,093 | -34 |
| Judith Basin | 2,044 | 2,017 | 27 |
| Meagher | 1,964 | 1,925 | 39 |
| Powder River | 1,702 | 1,693 | 9 |
| McCone | 1,718 | 1,733 | -15 |
| Daniels | 1,686 | 1,658 | 28 |
| Garfield | 1,209 | 1,172 | 37 |
| Carter | 1,428 | 1,413 | 15 |
| Prairie | 1,091 | 1,076 | 15 |
| Wibaux | 934 | 928 | 6 |
| Golden Valley | 831 | 820 | 11 |
| Treasure | 768 | 761 | 7 |
| Petroleum | 519 | 498 | 21 |