Middleton, previously known as Stringtown, is an unincorporated community in Washington County, Oregon, United States. To improve communication between Portland and Lafayette, a post office was established at Middleton in 1869. A rail station was then established on July 1, 1892, soon before the post office closed, in 1905. A November 2011 vote for the annexation of portions of Middleton north of Brookman Road by the neighboring incorporated community of Sherwood failed.