The County in 1855[11] purchased the original Courthouse site on which stood a mercantile store called Kays Adobe.

The new Courthouse (including approximately 148,000 square feet[13] of work space) was completed in March 1929 and dedicated on August 14, 1929.

In 1960, the Santa Barbara County Board of Supervisors Assembly Room was relocated and the courthouse was remodeled to add additional courtrooms.

The jail cells include tool proof bars and are constructed similar to the Alcatraz Federal Penitentiary in San Francisco, California.

Constructed in 2003,[17] the geothermal field provides a sustainable source of energy, powering the building's heating and cooling systems.

While unseen, this geothermal field is vital to the Courthouse's operation, showcasing innovation and environmental responsibility within a historical landmark.

In 1925, the County’s Board of Supervisors hired the William Mooser Company[5] of San Francisco to design and build the Courthouse in a Spanish-Andalusian castle style.

[13]  With its red tiled roofs, white stucco walls and various balconies, the Courthouse could be a castle in Andalusia.

Castle defenders would have stood on the Hoard and used the attendant “Lancet” windows to direct weapons fire down upon potential enemies.

The Courthouse includes a number of lamps varying in size and chandeliers custom made in the United States.

[20]  The Mural Room walls were painted by book illustrator and Hollywood set and costume designer Dan Sayer Groesbeck.

First displayed at the California Pacific International Exhibition in San Diego in 1935, the map was installed in the Santa Barbara County Courthouse in 1936.

The exterior features red tile roofs and white stucco walls consistent with the Spanish Colonial Revival style.

The rear exit of the Courthouse on the old jail side includes a dramatic 21 foot tall castle iron lattice gate (or yett).

[23] The courthouse grounds feature the Sunken Garden,[24] a prominent Santa Barbara park used year round for special events, Old Spanish Days[25] performances and weddings.

It features stone elements that roughly approximate the foundation of the Greek Revival courthouse that stood in this location up until 1925.

[26]  California Attorney General, Senator and United States Vice President Kamala Harris married Doug Emhoff at the Courthouse in 2014.

The clock tower's top floor includes an observation deck affording guests a 360-degree view of downtown Santa Barbara, the surrounding mountains, and the Pacific Ocean.

[14] Visitors may take elevators to the summit of the 85 ft (26 m) "El Mirador" clock tower, which has labeled photographs that show what the viewer is looking at in all directions.

In 1981, the Santa Barbara County Board of Supervisors designated the Docent Council as the official building host.