The Ventura Freeway is a freeway in southern California, United States, that runs from the Santa Barbara/Ventura county line to Pasadena in Los Angeles County. It is the principal east–west route through Ventura County and in the southern San Fernando Valley in Los Angeles County. From the Santa Barbara County line to its intersection with the Hollywood Freeway in the southeastern San Fernando Valley in Los Angeles, it is signed as U.S. Route 101 (US 101), which was built in the late 1950s and opened on April 5, 1960. The segments from the Santa Barbara County line to Sea Cliff, and from Solimar Beach to Oxnard, are also concurrent with State Route 1 (SR 1), although no signs mention SR 1 there. East of the Hollywood Freeway intersection, the Ventura Freeway is signed as State Route 134 (SR 134), which was built by 1971.

The Hollywood Freeway is one of the principal freeways of Los Angeles, California and one of the busiest in the United States. It is the principal route through the Cahuenga Pass, the primary shortcut between the Los Angeles Basin and the San Fernando Valley. It is considered one of the most important freeways in the history of Los Angeles and instrumental in the development of the San Fernando Valley. It is the second oldest freeway in Los Angeles. From its southern end at the Four Level Interchange to its intersection with the Ventura Freeway in the southeastern San Fernando Valley, it is signed as part of U.S. Route 101. It is then signed as State Route 170 north to its terminus at the Golden State Freeway.