Sammamish is a city in King County, Washington, United States. The population was 67,455 at the 2020 census. Located on a plateau, the city is bordered by Lake Sammamish to the west and the Snoqualmie Valley to the east. Sammamish is situated 20 miles east of Seattle, is a member of the Eastside, and is a part of the Seattle metropolitan area. Sammamish is an affluent community and has been ranked as one of the wealthiest cities in Washington.

King County is located in the U.S. state of Washington. The population was 2,269,675 in the 2020 census, making it the most populous county in Washington, and the 12th-most populous in the United States. The county seat is Seattle, also the state's most populous city.