Renton, city (1990 pop. 41,688), King co., W Wash., an industrial suburb of Seattle, on Lake Washington; inc. 1901. It is a freshwater port of entry via the Lake Washington Ship Canal. Its first important industries were coal mining, lumbering, and brickmaking. Railroad cars became important in the 1920s. Today the city has diverse manufactures, including aircraft (Boeing has had a plant there since World War II), trucks, and computer software. The city has a municipal airport, flying schools, and a seaplane base.