Mercer Island Flag

Mercer Island

County:
King County
County Seat:
No
Area (mi²):
6.383
State:
Washington

Mercer Island is a city located in King County, Washington. Mercer Island has a 2025 population of 24,072. Mercer Island is currently declining at a rate of -1.37% annually and its population has decreased by -6.51% since the most recent census, which recorded a population of 25,747 in 2020.

The average household income in Mercer Island is $303,425 with a poverty rate of 4.64%.The median age in Mercer Island is 45.8 years: 45.5 years for males, and 46.1 years for females.

24.1K
Total Population
3,771
Density (mi²)
-335 -1.37%
Growth

Mercer Island Population

Demographics

Economics and Income Statistics

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)