Gallatin County's 2026 population is estimated at 129,094, reflecting a 0.82% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Gallatin County is the 2nd largest county in Montana. The 2010 population was 89,662 and has grown 43.98% since 2010.
Data after 2023 is projected based on recent change
Overall: 34.2 years
Female: 35.1 years
Male: 33.2 years
There are 100,769 adults, (16,865 of whom are seniors) in Gallatin County.
Female: 59,123 (47.7%)
Male: 64,951 (52.3%)
The racial composition of Gallatin County includes 88.8% White, and smaller percentages for other race, Asian, Native American, Black or African American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 110,173 | 88.8% |
| Two or more races | 8,455 | 6.81% |
| Other race | 2,563 | 2.07% |
| Asian | 1,560 | 1.26% |
| Native American | 755 | 0.61% |
| Black or African American | 555 | 0.45% |
| Native Hawaiian or Pacific Islander | 13 | 0.01% |
Gallatin County 's average per capita income is $57,338. Household income levels show a median of $93,528. The poverty rate stands at 9.52%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $128,619 | $177,537 |
| Families | $117,341 | $162,320 |
| Households | $93,528 | $132,508 |
| Non Families | $62,039 | $88,943 |
Average Income
Median Household Income
Poverty Rate
