Mercer Island, Washington

Mercer Island, Washington
Aerial view of Mercer Island from the north
Location of Mercer Island in King County, Washington
Coordinates: 47°34′24″N 122°14′19″W / 47.57333°N 122.23861°W / 47.57333; -122.23861
CountryUnited States
StateWashington
CountyKing
IncorporatedJuly 5, 1960
Government
  TypeCouncil–manager
  MayorSalim Nice
  Deputy MayorDavid Rosenbaum
  CouncilmemberJake Jacobson
Craig Reynolds
Wendy Weiker
Ted Weinberg
Area
  Total
12.90 sq mi (33.41 km2)
  Land6.38 sq mi (16.53 km2)
  Water6.52 sq mi (16.88 km2)
Elevation
75 ft (23 m)
Population
 (2020)
  Total
25,748
  Estimate 
(2023)
24,742
  Density3,880/sq mi (1,497/km2)
Time zoneUTC−8 (Pacific (PST))
  Summer (DST)UTC−7 (PDT)
ZIP Code
98040
Area code206
FIPS code53-45005
GNIS feature ID2411082
Websitemercerisland.gov

Mercer Island is a city in King County, Washington, United States, located on an island of the same name in the southern portion of Lake Washington. Mercer Island is in the Seattle metropolitan area, with Seattle to its west and Bellevue to its east.

The island is connected to the mainland on both sides by bridges carrying Interstate 90, with the city of Seattle to the west and the city of Bellevue to the east. The Lacey V. Murrow Memorial Bridge and the parallel Homer M. Hadley Memorial Bridge are floating bridges that span Lake Washington and carry, respectively, eastbound and westbound lanes of Interstate 90 and connect Mercer Island to the northern portion of Seattle's South End. I-90 traverses the northern portion of Mercer Island and is then carried from the island to Bellevue over the East Channel of Lake Washington by the East Channel Bridge. Mercer Island is located closer to Bellevue than it is to Seattle, and is therefore often considered to be part of King County's Eastside.

The population was 25,748 at the 2020 census. Mercer Island is one of the 100 richest ZIP codes in the US according to the IRS figures for Adjusted Gross Income.