Montana 2020 Census Total Population By County

The total population of Montana from the 2020 Census was 1,084,225, based on data from the US Census Bureau.

Yellowstone County was the most populated county (164,731), followed by Gallatin County (118,960), and then Missoula County (117,922). On the other hand, the 3 counties that were least populated include: Petroleum County (496), Treasure County (762), and Golden Valley County (823).

You can also see this information for other states and also for the US by state.

Hover over or click on the counties to see the number and percentage of Montana population that lives in each county. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.

You can also see the population by county for the different racial groups as well as the different ethnicities in Montana.