| Place Name | Lake Cassidy |
| Place Type | Census Designated Place |
| ZIP Code(s) | 98223 98258 98270 |
| County | Snohomish County |
| Area Code(s) | 360,425 |
| Timezone | Pacific Daylight Time (PDT) |
| Population (2022) | 3,754 |
| Population Growth Rate (2010-19) | 10.01% |
| Majority Ethnicity | White 93.81% |
| Metro/Micro Stats Area | Seattle-Tacoma-Bellevue, WA |
| US Congressional District(s) | Washington 1stWashington 2nd |
| State House Districts | 39,44 |
| State Senate Districts | 39,44 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 93.81% |
| African American | 0% |
| Hispanic | 0.49% |
| Asian | 0.87% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 4.83% |