| Place Name | Mercer Island |
| Place Type | City |
| ZIP Code(s) | 98040 |
| County | King County |
| Area Code(s) | 206 |
| Timezone | Pacific Daylight Time (PDT) |
| Population (2022) | 22,922 |
| Population Growth Rate (2010-19) | 13.43% |
| Majority Ethnicity | White 72.54% |
| Metro/Micro Stats Area | Seattle-Tacoma-Bellevue, WA |
| US Congressional District(s) | Washington 9th |
| State House Districts | 41 |
| State Senate Districts | 41 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 72.54% |
| African American | 0.96% |
| Hispanic | 0.07% |
| Asian | 22.87% |
| Native American | 0.11% |
| Hawaiin/Pacific Islander | 3.44% |