José Castro (b. Monterey, 1808 - February 1860) was acting governor of Alta California in 1835-1836, and Commandante General of the Mexican army in Alta California at the time of the 1846 Bear Flag Revolt in and the Mexican-American War of 1846-1848. He was the son of Joaquín Ysidio Castro, a soldier in Spanish commander Juan Bautista de Anza's expedition of 1775-1776. José Castro acquired Rancho San Justo, one of three ranchos attached to Mission San Juan Bautista, after the secularization of Mission property by the Mexican government in 1832-1833.

Castro's sister, Martina Cota Castro (1807-1890), held the grant for Rancho Soquel which is now part of Soquel, California. Martina Castro married Michael Lodge, and together had a daughter, Carmelita (Carmel) Castro Lodge (1827-1923) who later married Thomas Fallon in 1850. The Victorian at 1800 Market Street, San Francisco, was built by Carmel in 1894 and is now an SF landmark known as the Carmel Fallon Building.

In the late 1850s José Castro was also governor of Baja California and a Brigadier General in the Mexican Army. He never surrendered his Mexican citizenship nor military rank. In February 1860, Governor Castro was assassinated by the bandit Marguez.

Castro Street and the Castro District in San Francisco are named after him.