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.

The city lies along the Sammamish River, the historic home of the indigenous Sammamish people, and is adjacent to Kenmore and Woodinville. It was established in 1870 and platted by David Bothell and his family in 1888, shortly before the arrival of railroads in the area. The town was incorporated in 1909 and originally relied on logging and farming; in the mid-20th century, it became a bedroom community for workers commuting to Seattle and later other Eastside cities. Interstate 405 connects the city to other areas of the Eastside and functions as a bypass of Seattle.

Bothell's modern economy is centered around biotechnology and high-tech companies that have facilities that were developed in the late 20th century along North Creek and in the Canyon Park neighborhood, which was annexed by the city in 1992. The annexation also expanded the city limits into Snohomish County. The University of Washington Bothell was established in 1990 and opened its permanent shared campus with Cascadia College in 2000. Bothell redeveloped its downtown in the 2010s and 2020s and has seen an increase in residential density and its population as a result.