King County is named for William R King, who was a United States Vice President under Franklin Pierce and In 1986 named for Martin Luther King Jr., who was a civil rights activist.
Surrounding County Courthouses:
N – Snohomish County
E – Chelan County and Kittitas County
S – Pierce County
W – Pierce County and Kitsap County
Created: December 22, 1852
County Seat:
Seattle 1852 – present
County Courthouse – Seattle
Location: 516 3rd Avenue / James Street
Built: 1916 – 1917
Style: Beaux Arts
Architect: A Warren Gould
Contractor: Puget Sound Bridge & Dredging Company
Description: The building faces north and is a twelve story brick, steel and concrete structure. The building is located in the center of Seattle. There are west and east wings which are joined by a center section forming an ”H” design. The roof line is flat. The interior of the building is elegant and modern. The main entrance facing Jefferson Street has a grand staircase of green and white marble leading up to the second floor. The ceiling is vaulted with acorn-shaped pendant lights hanging from each vault. The interior walls and floors contain two and one half acres of Alaska marble. The County Superior Court courtrooms are located on the second and third stories. The building houses the County Superior Court. In 1930, six stories were added to the existing five stories and completed in 1931. The architect for the second phase was Henry Bittman and John L McCauley and the contractor was Hans Pederson. In 1967, a large remodeling project was undertaken by the architectural firm of Paul Delaney and Associates. The building was remolded in 2006. The architect was Freeman Fong.
History: The county was created in 1852 and Seattle was selected as the county seat. The first county meetings were held at the cook house of Henry Yesler. The first courthouse was built in 1860 on Prefontaine Place at a cost of $444 on land owned by Henry Yesler. The court met in the Snoqualmie Hall from 1859 until 1866, and then in Yeslewr’s Hall and the Yesler’s Pavilion until 1876. The second courthouse was a two story wood, stone and brick structure built at Third and Jefferson at a cost of $17,000. The first courtroom was added in 1881. The third courthouse was designed by W A Ritchie and built by Robert Smillie in 1889 to 1890 at 7th and Alder at a cost opf $200,000. In 1906, the Yesler Mansion was purchased at Third and James for $235,000 and the third and present courthouse was constructed on the site in 1914 to 1916 at a cost of $1,271,646.
County Administration Building – Seattle

Location: 500 4th Avenue / James Street
Built: 1969 – 1971
Style: Modern
Architect: Harmon Pray Detrich, Architects
Contractor: Sellen Construction Company
Description: The building faces east and is a multi-story concrete and glass structure. The building is located in the center of Seattle on the east side of the courthouse. The building houses offices of the County Executive , County Council, and County court system.
See: Located in the county is the Washington Court of Appeals – Seattle.

County Courthouse – Seattle









County Superior Court courtroom





King County Administration Building – Seattle





Photos taken 2009 and 2016