| Place Name | Three Mile Bay |
| Place Type | Census Designated Place |
| ZIP Code(s) | 13693 |
| County | Jefferson County |
| Area Code(s) | 315,680 |
| Timezone | Eastern Daylight Time (EDT) |
| Population (2022) | 144 |
| Population Growth Rate (2010-19) | -17.62% |
| Majority Ethnicity | White 100% |
| Metro/Micro Stats Area | Watertown-Fort Drum, NY |
| US Congressional District(s) | New York 21st |
| State Assembly Districts | 116 |
| State Senate Districts | 48 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 100% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0% |