Sonoma County is named for the town of Sonoma which began with the foundation of the Mission San Francisco Solano in 1823.
Surrounding County Courthouses:
N – Mendocino County
E – Lake County and Napa County
S – Contra Costa County and Marin County
W – Pacific Ocean
Created: February 18, 1850 
County Seat:
Santa Rosa 1850 – present
County Hall of Justice – Santa Rosa
Location: 600 Administration Drive / Ventura Avenue
Built: 1963 – 1965
Style: Modern
Architect: J Clarence Felciano & Associates
Contractor: Guy F Atkinson Company
Description: The building faces south and is a two and three story concrete, red colored brick and glass structure. The building is located on landscaped grounds of the County Complex to the north of the center of Santa Rosa. A large quadrangle is at the center and the roof line is flat. The building houses the County Superior Court – Criminal and Juvenile.
County Courthouse Annex – Santa Rosa
Location: 3035 / 3055 Cleveland Avenue / Russell Avenue
Built: 1968 – 2000
Style: Modern
Architect: Glass Architects
Contractor: Unknown
Description: The buildings face east and are two three story concrete, red colored brick and glass structures. The buildings are located on landscaped grounds of Empire College to the north of the center of Santa Rosa and west of the County Hall of Justice. The rectangular shaped building on the north side houses the County Superior Court – Civil and Family Law. The large building on the south side houses the County Superior Court – Civil and the law school.
New County Hall of Justice – Santa Rosa
Location: 600 Administration Drive / Ventura Avenue
Built: 2021 – 2023
Style: Modern
Architect: STUDIOpractice (Richard Meier & Partners Architects )
Contractor: AECOM
Description: The building faces south and is a six story concrete and glass structure. The building is located on landscaped grounds of the County Complex to the north of the center of Santa Rosa. The building contains fifteen courtrooms.
See: The county is located in the 1st Appellate District of the Court of Appeal – San Francisco.
History: The county was created in 1850 and Sonoma was selected as the county seat. The county rented a building owned by Judge H A Green and the building was purchased as the first courthouse. The county seat was moved to Santa Rosa in 1854 and the court met in the old Masonic Hall until the second courthouse was built in 1854 at the corner of Fourth Street and Mendocino Street. The third courthouse was built in 1854 to 1855 at a cost of $40,891 after the building was expanded in 1855 and a second story was added in 1859 to 1860. The fourth courthouse was large granite structure designed by A A Bennett and J M Curtis and constructed by Carle & Croly in 1883 to 1885 at a cost of $80,000. The building was destroyed by earthquake in 1960. The fifth courthouse was designed by J W Dolliver and constructed in 1910. The building damaged by the 1957 earthquake and the building was razed in 1966 creating Old Courthouse Square in the center of Santa Rosa. The fourth courthouse was the Hall of Justice constructed in 1963 to 1965. The new Hall of Justice ia under construction at a cost of $186,364,000.
County Hall of Justice – Santa Rosa
County Courthouse Annex – Santa Rosa
Old Courthouse Square – Santa Rosa
Photos taken 2015
Images 23