List of U.S. Routes in Washington

U.S. Routes in Washington
Highway markers in different years for former U.S. Route 10 (1926), former U.S. Route 99 (1961), and current U.S. Route 101 (1970)
The state highway system of Washington, with U.S. routes highlighted in red.
System information
Length:	1,390.63 mi (2,238.00 km)
Formed:	November 11, 1926
Notes:	Maintained by WSDOT
Highway names
US Highways:	U.S. Route nn (US nn)
Alternate Routes:	U.S. Route nn Alternate (US nn Alt)
Spur Routes:	U.S. Route nn Spur (US nn Spur)
System links
State highways in Washington Interstate US State Scenic Former PSH 1964 renumbering Former

The U.S. routes in Washington are United States Numbered Highways that are owned and maintained by the U.S. state of Washington through the Washington State Department of Transportation (WSDOT). The United States Numbered Highway System in Washington covers 1,390.63 miles (2,238.0 km) and consists of eight highways, divided into four primary routes and four auxiliary routes.

The United States Numbered Highway System was approved and established on November 11, 1926 by the American Association of State Highway Officials (AASHO) and included eleven routes traveling through Washington.