Arlington is a city in northern Snohomish County, Washington, United States, bordered by the city of Marysvilleto the south. The population was 17,926 at the 2010 census.
Arlington was platted by European Americans in 1900, and was named after Lord Henry Arlington, a member of Charles II of England's cabinet. Haller City was a nearby town founded April 24, 1890, by Theodore Hallerand his parents Henrietta and Granville O. Haller. When Arlington was incorporated as a city in May 5, 1903, it included Haller City. The city is home to the Stillaguamish Valley Pioneer Museum.Prior to European settlement, the area was inhabited by Indigenous Americans, whose descendants identify as the Stillaquamish Tribe.