City in Richland County, Montana · 3.3 sq mi · 1,868 people per sq mi
6,140 people live in Sidney. The typical household earns $62,538, and the median resident is 37.3 years old.
2026 projection
From 6,346 in 2020
Poverty rate 7.7%
Men 37.1 · Women 37.3
1900–2026
6,140
2026 projection
3.2% since 2020 (decrease)
Source: U.S. Census Bureau decennial counts and annual estimates, including 2010–2020 intercensal estimates. 2026 is a projection. Values between recorded years are interpolated.
Use the left and right arrow keys to inspect population observations.
1900–2026
6,140
2026 projection
3.2% since 2020 (decrease)
Source: U.S. Census Bureau decennial counts and annual estimates, including 2010–2020 intercensal estimates. 2026 is a projection. Values between recorded years are interpolated.
Use the left and right arrow keys to inspect population observations.
| 2026 | 6,140 | -77 | 1.24% |
|---|---|---|---|
| 2025 | 6,217 | +166 | 2.74% |
| 2024 | 6,051 | -19 | 0.31% |
| 2023 | 6,070 | -57 | 0.93% |
| 2022 | 6,127 | -102 | 1.64% |
| 2021 | 6,229 | -117 | 1.84% |
| 2020 | 6,346 | +28 | 0.44% |
| 2019 | 6,318 | -12 | 0.19% |
| 2018 | 6,330 | -87 | 1.36% |
| 2017 | 6,417 | -195 | 2.95% |
Showing 10 of 28 years.
The 2020 row compares the April 1 Census count with the July 1, 2019 estimate (about nine months). Its Growth and Annual change therefore do not represent a full year.
Sidney has a population change lower than Richland County, Montana, and the U.S.
Change from July 1, 2020 to July 1, 2025 population estimates—not annualized growth or site projections.
Source: U.S. Census Bureau. U.S. totals are summed from the 50 states and D.C.; unavailable comparisons are omitted.
U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101
Each square is about 1% of residents (roughly 62 people).
Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.
U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002
Half of households earn more, half earn less
Typical yearly pay for a worker 25 or older.
About 1 in 13 residents
44% of residents age 15 and older are married.
| Status | Overall | Male | Female |
|---|---|---|---|
| Married | 44% | 43% | 46% |
| Never married | 35% | 41% | 29% |
| Divorced | 14% | 13% | 16% |
| Widowed | 6% | 1% | 10% |
| Separated | 1% | 2% | <1% |
U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201
14 sources