The Santa Cruz Mountains are a mountain range in central California forming a ridge along the peninsula south of San Francisco that separates the Pacific Ocean from San Francisco Bay and the Santa Clara Valley. The tallest peak in the range is Loma Prieta (1160 m; 3806'), near which is the epicenter of the 1989 Loma Prieta earthquake. Other major peaks include Mt. Umunhum (1063 m; 3486'), Mt. Bielawski (985 m; 3231'), El Sombroso (914 m; 2999'), Eagle Rock (758 m; 2488') and Morena Sierra (737 m; 2417'). The San Andreas Fault runs along or near the ridge line throughout the range.

The area welcomes a tremendous number of species of birds. (see: bird list)

The Santa Cruz Mountains are home to the southernmost coast redwoods.