Vashon is a census-designated place (CDP) in King County, Washington, United States.

In the CDP, the population was spread out with 23.2% under the age of 18, 4.6% from 18 to 24, 25.1% from 25 to 44, 34.0% from 45 to 64, and 13.1% who were 65 years of age or older. The median income for a household in the CDP was $58,261, and the median income for a family was $67,010.

Males had a median income of $50,201 versus $36,426 for females. About 4.6% of families and 6.0% of the population were below the poverty line, including 5.2% of those under the age of 18 and 2.2% of those 65 and older.

23.8% of all households were made up of individuals and 8.0% had someone living alone who was 65 years of age or older.

The average household size was 2.40 and the average family size was 2.86. For every 100 females age 18 and over, there were 91.0 males.

Water Taxi service between the northern terminus and downtown Seattle for passengers only is provided by King County with three sailings in each direction during both the morning and afternoon, Monday through Friday.

Vashon Municipal Airport is on the northern half of the island.

European-Americans settled Vashon Island between 18. During that time the main economies on the island were fishing and logging.

In 1890, Vashon Islanders started growing strawberries for sale.

During its operation, it was one of the leading colleges in the area. At that time, Vashon Island was separate from the neighboring Maury Island, but today the hamlet of Portage sits on an isthmus built in 1916 by local homeowners that connects the two.

According to the United States Census Bureau, the CDP has a total area of 37.0 square miles (96 square kilometres).

Vashon's economy took another hit in recent years when it lost two of its major industrial employers: K2 Sports moved its manufacturing to China, and the Seattle's Best Coffee roastery operation was closed shortly after SBC was bought by Starbucks.