Bothell is a city in King and Snohomish counties in the U.S. state of Washington. It is part of the Seattle metropolitan area, situated near t…Bothell is a city in King and Snohomish counties in the U.S. state of Washington. It is part of the Seattle metropolitan area, situated near the northeast end of Lake Washington in the Eastside region. It had a population of 48,161 residents as of the 2020 census.