State Route 34 (SR 34) is a short state highway in the U.S. state of California.

SR 34 is part of the California Freeway and Expressway System.

It starts on the west at the intersection of Oxnard Boulevard (Route 1) and Fifth Street in Oxnard. It continues east then northeast on Fifth Street until it intersects Pleasant Valley Road in Camarillo. After continuing east on Pleasant Valley Road a short distance, it turns north onto Lewis Road until the intersection with Las Posas Road at the north city limit of Camarillo where Route 34 continues straight ahead as Somis Road. It ends at Route 118 near Somis. This route originally began in Port Hueneme, but in 1965, the portion from Port Hueneme to Route 1 was deleted. Nevertheless, Route 34 mileposts add on these additional 4 miles (6.4 km) along the signed route.

The route parallels the Southern Pacific Coast Line, which carries Coast Starlight, Pacific Surfliner and Metrolink Ventura County Line passenger trains, for almost its entire current length.

According to the 2003 Caltrans District 7 Master System Plan Status Map, the segment of California Route 34 on Fifth Street and Pleasant Valley Road will be relocated to a north–south alignment beginning near Calleguas Creek opposite the Naval Air Weapons Station, Point Mugu on California Route 1 and ending near the intersection of Lewis and Pleasant Valley roads.

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, and do not necessarily reflect current mileage. The entire route is in Ventura County.