Mission Boulevard (East Bay, California)

State Route 238
SR 238 highlighted in red
Route information
Defined by
Maintained by Caltrans
Length:	14.393 mi (23.163 km)
Existed:	July 1, 1964 – present
Major junctions
South end:	I-680 in Fremont
	SR 92 / SR 185 in Hayward
North end:	I-238 / I-580 in Castro Valley
Location
Counties:	Alameda
Highway system
State highways in California Interstate U.S. State Pre-1964 History Unconstructed Deleted Freeway Scenic ← I-238 SR 241 →

State Route 238 (SR 238) is a north–south highway in the U.S. state of California. The route is a divided multilane surface highway in the southeastern part of the San Francisco Bay Area. SR 238 connects Interstate 580 in Castro Valley and Interstate 680 in Fremont.

SR 238 goes through Hayward and Union City parallel to the Hayward hills. It formerly contained a segment of east–west freeway now designated as Interstate 238 and, until Interstate 680 was completed in the area and supplanted it completely as a through route, extended to San Jose, California at its intersection with U.S. Route 101. Locally it is designated Mission Boulevard from I-680 to the intersection with State Route 92 and State Route 185 (which continues as Mission Boulevard). It is designated as Foothill Boulevard in northern Hayward from A Street to I-580.

In Downtown Hayward immediately north of SR 92, northbound traffic continues along the original SR 238 alignment on Foothill Boulevard, while southbound traffic is diverted onto A Street and Mission Boulevard. This loop of one-way streets is known as the "Hayward Loop".