Loma Prieta, Mountain summit in the Santa Cruz Mountains, California, United States

Loma Prieta is the highest summit of the Santa Cruz Mountains in Northern California, reaching 3,790 feet (1,160 m). The peak lies on private land and is closed to public access. An unpaved road leads to the summit, which is occupied by numerous transmission facilities.

In the 19th century the peak was called Mount Bache, after Alexander Dallas Bache, a name no longer used. From 1955 to 2005 it hosted the transmitter tower of San Jose station KNTV, which moved 83 km northwest to San Bruno Mountain in September 2005 after becoming the Bay Area's NBC affiliate. The 1989 Loma Prieta earthquake took its name from the mountain, though its epicenter lay five miles southwest, across the San Andreas Fault in The Forest of Nisene Marks State Park.

The name comes from Spanish words meaning 'dark hill', a remnant of early Spanish settlement in Northern California. This naming reflects how the landscape was described based on what people saw.

The mountain stands on private land and requires special permission to access the summit. Visitors should check in advance since regular hiking is not permitted.

From 1976 to 1990 Donald Machholz set up his telescope on the south slope an average of 120 nights a year, discovering three comets there, among them 96P/Machholz on 12 May 1986. The first official West Coast Messier marathon was held at the same site in March 1979.