How many people live in Gallatin County, MT?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 127,000 people living in Gallatin County, MT. That makes Gallatin County the second-most populous county in Montana. It is home to 11.1% of people living in the state.
127K
population of Gallatin County, MT (2024)
11.1%
County share of the Montana population (2024)
About 127,000 people lived in Gallatin County, MT in 2024.
Population estimates, 2000–2024
What are Gallatin County, MT’s age demographics?
About 18,200 Gallatin County, MT residents are aged 65 and older in 2024. That represents 14.3% of its population. For comparison, the age group represents 21.1% of Montana’s population and 18% in the US overall.
Another 23,100 Gallatin County residents, or 18.2% of the population, were children under 18. For comparison, the age group represents 20.5% of Montana’s population and 21.6% in the US overall.
A higher share of Gallatin County, MT's population is aged 18–24 than the US as a whole.
Population estimates by age group, (2024)
What are Gallatin County, MT’s racial and ethnic demographics?
Non-Hispanic white residents make up 89.1% of the Gallatin County, MT population, higher than the national share of 57.5%. Gallatin County, MT also has a larger share of people identifying as non-Hispanic American Indian and Alaska Native (0.81%) than the US overall (0.72%).
In contrast, Gallatin County’s Hispanic population accounts for 5.8%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 0.57% of the county, compared with 12.6% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Gallatin County, MT has a higher share of a non-Hispanic white population than Montana as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Gallatin County, MT is Bozeman with about 57,900 residents in 2024.
Cities and towns in Gallatin County, MT ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Bozeman | 57,894 |
| 2. | Belgrade | 12,741 |
| 3. | Manhattan | 2,068 |
| 4. | Three Forks | 1,945 |
| 5. | West Yellowstone | 1,202 |
| 6. | Balance of Gallatin County | 51,134 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
