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. Incorporated in 1999, Sammamish is an affluent community and has been ranked as one of the wealthiest cities in Washington.