Alder
- County:
- Pierce County
- County Seat:
- No
- Area (mi²):
- 3.213
- State:
- Washington
Alder is a CDP located in Pierce County, Washington. Alder has a 2025 population of 98 . Alder is currently declining at a rate of -8.41% annually and its population has decreased by -26.87% since the most recent census, which recorded a population of 134 in 2020.
The median age in Alder is 38 years: 39.6 years for males, and 37.5 years for females. For every 100 females there are 83.3 males.