The 1863 United States Senate election in California was held on February 10, 1863, by the California State Legislature to elect a U.S. senator (Class 1) to represent the State of California in the United States Senate. In a special joint session, former Democratic State Assemblyman John Conness was elected over fellow Democratic State Senator Benjamin Shurtleff. Conness was supported by the Union Party, while Shurtleff (despite being a unionist himself) was supported by the Chivalry Democrats.