Tanasbourne, Oregon, is a neighborhood in Washington County, Oregon, where NW 185th Avenue and the Sunset Highway (part of U.S. Highway 26) intersect. It is located within the Portland metropolitan area. The area sits between Beaverton and Hillsboro, and is generally considered to be south of U.S. 26, north of Walker Road, west of 158th, and east of Cornelius Pass Road.