Montana Population By County (2018)
Created on February 25, 2020.
Data Updated on May 9, 2021.

According to the US Census Bureau population estimates, there were 1,060,665 people living in Montana in 2018. Yellowstone County was the most populated county with 160,029 residents, followed by Missoula County with 118,640 residents, and Gallatin County with 111,682 residents. Petroleum County with a population of 512 was the least populated county in Montana in 2018.

Use the map below to interactively explore the population of each county in Montana in 2018. The data can also be explored further by sorting and filtering with the table below.

Hover/Click on the counties to see the values.
Montana Population By County (2018)
Table of Montana Population By County (2018)
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County Population % of State Population
Beaverhead 9,412 0.89%
Big Horn 13,365 1.26%
Blaine 6,774 0.64%
Broadwater 6,072 0.57%
Carbon 10,691 1.01%
Carter 1,230 0.12%
Cascade 81,688 7.70%
Chouteau 5,740 0.54%
Custer 11,592 1.09%
Daniels 1,729 0.16%
Dawson 8,680 0.82%
Deer Lodge 9,129 0.86%
Fallon 2,912 0.28%
Fergus 11,117 1.05%
Flathead 102,017 9.62%
Gallatin 111,682 10.53%
Garfield 1,257 0.12%
Glacier 13,828 1.30%
Golden Valley 822 0.08%
Granite 3,371 0.32%
Hill 16,342 1.54%
Jefferson 12,094 1.14%
Judith Basin 1,946 0.18%
Lake 30,220 2.85%
Lewis and Clark 68,622 6.47%
Liberty 2,416 0.23%
Lincoln 19,797 1.87%
McCone 1,669 0.16%
Madison 8,530 0.80%
Meagher 1,857 0.18%
Mineral 4,307 0.41%
Missoula 118,640 11.19%
Musselshell 4,632 0.44%
Park 16,648 1.57%
Petroleum 512 0.05%
Phillips 4,060 0.38%
Pondera 5,960 0.56%
Powder River 1,720 0.16%
Powell 6,953 0.66%
Prairie 1,070 0.10%
Ravalli 43,166 4.07%
Richland 10,855 1.02%
Roosevelt 11,069 1.04%
Rosebud 9,040 0.85%
Sanders 11,847 1.12%
Sheridan 3,386 0.32%
Silver Bow 34,739 3.28%
Stillwater 9,483 0.89%
Sweet Grass 3,703 0.35%
Teton 6,117 0.58%
Toole 4,835 0.46%
Treasure 673 0.06%
Valley 7,406 0.70%
Wheatland 2,184 0.21%
Wibaux 1,030 0.10%
Yellowstone 160,029 15.09%