List of state highways in California

This is a list of state highways in the U.S. state of California that have existed since the 1964 renumbering. It includes routes that were defined by the California State Legislature but never built, as well as routes that have been entirely relinquished to local governments. It does not include the few routes that were relinquished before 1964 or the larger number of sign routes that were renumbered in or before 1964.

Notes

• If a route was renumbered, the old or new number is given in the "formed" or "deleted" column.
• The years are when legislative action was taken, not when real-world changes were made. Most notably, SR 275 was deleted from the Streets and Highways Code in 1996, but remains partially maintained, and SR 42 was signed as such for over 30 years after it was renumbered 105.
• Since the 1990s, a number of piecemeal relinquishments have been made. These are generally reflected in the length but not the termini.
• Former termini are not shown if they are along the current route, meaning that the route was simply extended.
• One Interstate Highway - Interstate 305 - is defined only federally; the state calls it part of US 50. It is signed as part of Business 80, the only state-maintained Interstate business route in California.