The 2nd Regiment California Volunteer Infantry was an infantry regiment in the Union Army during the American Civil War. It spent its entire term of service in the western United States. Organized at San Francisco and Carson City September 2, 1861, to December 30, 1862 and attached to Department of the Pacific. The regiment was first assembled at the Presidio, San Francisco, and after completing its organization, five companies were sent to Oregon and Washington Territory, to relieve the regular troops, and two companies were sent to Santa Barbara. The troops of this regiment sent to Oregon were afterwards returned to California. It was mustered out during the month of October, 1864.