State Route 1, often called Highway 1, is a state highway that runs along a large length of the Pacific coast of the U.S. state of California. It is famous for running by some of the most beautiful coastlines in the world, leading to its designation as an All-American Road.

In Southern California, the California Legislature has designated the segment between Interstate 5 in Dana Point and U.S. Route 101 near Oxnard as Pacific Coast Highway (commonly referred to as PCH for short); between U.S. Route 101 at the Las Cruces junction (8 miles south of Buellton) and U.S. Route 101 in Pismo Beach and between U.S. Route 101 in San Luis Obispo and U.S. Route 101 in San Francisco, the legislature has designated State Route 1 as the Cabrillo Highway; and between Manzanita Junction near Marin City and U.S. Route 101 in Leggett, the legislature has designated State Route 1 Shoreline Highway. However, subsequent to naming the highway the Pacific Coast Highway, Cabrillo Highway, and Shoreline Highway, the legislature has given some segments of Route 1 additional names as described in the State Law section. In addition to this, some segments have been given alternative names by local governments.

This route is part of the California Freeway and Expressway System CA Codes (shc:250-257) and is eligible for the State Scenic Highway System.