State Route 55 (SR 55) is an 18-mile (30-km) long north–south state highway that passes through suburban Orange County in the U.S. state of California. The portion of the route built to freeway standards is known as the Costa Mesa Freeway (formerly the Newport Freeway). SR 55 runs between Via Lido south of Pacific Coast Highway (SR 1) in Newport Beach and the Riverside Freeway (SR 91) in Anaheim to the north, intersecting other major Orange County freeways such as SR 22, SR 73, and Interstate 405 (I-405).