| Place Name | Selden |
| Place Type | Census Designated Place |
| ZIP Code(s) | 11784 |
| County | Suffolk County |
| Area Code(s) | 631,934 |
| Timezone | Eastern Daylight Time (EDT) |
| Population (2022) | 19,978 |
| Population Growth Rate (2010-19) | 7.11% |
| Majority Ethnicity | White 73.59% |
| Metro/Micro Stats Area | New York-Newark-Jersey City, NY-NJ-PA |
| US Congressional District(s) | New York 1st |
| State Assembly Districts | 4,5 |
| State Senate Districts | 2 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 73.59% |
| African American | 3.7% |
| Hispanic | 0.04% |
| Asian | 5.38% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 17.28% |