State Route 25 is a state highway in the U.S. state of California between Gilroy and State Route 198. This route is part of the California Freeway and Expressway System and is eligible for the State Scenic Highway System.

SR 25 (also known as Bolsa Road and the Airline Highway) begins at the intersection of Peach Tree Road and State Route 198 east of Priest Valley, in Monterey County, and is the northern extension of Peach Tree Road. It heads northwest, crossing into San Benito County and passing through the community of Bitterwater. SR 25 provides access to the Pinnacles National Monument east entrance, running parallel to the San Andreas Fault. Running parallel to the Diablo Range, SR 25 passes through the communities of Paicines and Tres Pinos and the city of Hollister. SR 25 continues northwest from Hollister, intersecting with State Route 156, and ends at U.S. Route 101 in Gilroy.

One story of where the highway got its name is that before the advent of radio navigation, airline pilots flying north-south routes between San Francisco and Los Angeles would use this highway as a visual aid to confirm that they were on the correct route.

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 numbers reset at county lines; the start and end postmiles in each county are given in the county column.