| Place Name | Sidney |
| Place Type | City |
| ZIP Code(s) | 59270 |
| County | Richland County |
| Area Code(s) | 406 |
| Timezone | Mountain Daylight Time (MDT) |
| Population (2022) | 5,360 |
| Population Growth Rate (2010-19) | 22.25% |
| Majority Ethnicity | White 90.6% |
| US Congressional District(s) | Montana At-Large |
| State House Districts | 35 |
| State Senate Districts | 18 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 90.6% |
| African American | 0% |
| Hispanic | 0.22% |
| Asian | 0% |
| Native American | 1.96% |
| Hawaiin/Pacific Islander | 7.22% |