Mercer Island the only city in King County located on an island, and the only community in King County in which the boundary of the city and the school district are identical.

Mercer Island's six square miles are home to about 22,000 people. Because of its island character, Mercer Island has a strong sense of community. Residents refer to themselves as "Islanders" and take pride in the Island's friendly, small-town atmosphere.

Five miles long and 2 1/2 miles wide, Mercer Island is primarily a residential community. While most residents work in Seattle or Eastside cities, there is also growing number of residents who telecommute or operate home businesses. The proximity to Seattle, the low crime rate, and excellent schools have made Mercer Island one of the most desirable places to live in the Pacific Northwest.

The Island is home to executives and professionals. Its most famous resident is Paul Allen, co-founder of Microsoft and the fifth-richest person in the world according to Forbes magazine. Mercer Island's zip code, 98040, is the wealthiest in the state.