Onslow County is named for Arthur Onslow, who was the Speaker of the British House of Commons and who lived from 1691 to 1768.
Surrounding County Courthouses:
N – Jones County
E – Jones County and Carteret County
S – Atlantic Ocean
W – Pender County and Duplin County
Created: November 23, 1731 
County Seat:
New River 1734 – 1735
Joseph Howard Home 1735
Christian Heildberg Home 1735
Joseph Howard Home 1735 – 1737
New River 1737 – 1744
Johnston 1744 – 1753
James Foyle House 1753 – 1757
Wantland’s Ferry 1757 – 1842
Jacksonville 1842 – present
County Courthouse – Jacksonville
Location: 625 Court Street / Old Bridge Street
Built: 1904 – 1905
Style: Georgia Revival
Architect: B F Smith Fire-Proof Construction Company of Washington, DC
Contractor: B F Smith Fire-Proof Construction Company of Washington, DC
Description: The building faces south and is a two story red colored brick and concrete structure. The building has a one story portico at the front with six square pillars supporting a flat roof. A white colored horizontal band runs below the second story windows, and below the eaves. On the center of the roof is a square white colored cupola with green colored roof. The courtroom is located on the second story. The building houses the County Superior Court of the 4th Judicial District. The building was renovated in 1948. The architect was John J Rowland and the contractor was T A Loving & Company. The building was further renovated in 2000. The architect was Ellinwood Design Associates of Morehead and the contractor was Pro Construction Inc. of Jacksonville.
County Justice Center – Jacksonville
Location: 109 Old Bridge Street / Court Street
Built: 1976 – 1978
Style: Modern
Architect: Brennan Associates
Contractor: Brennan Associates ( supervisor of contractors )
Description: The building faces east and is a two story buff colored brick structure. The building faces east towards the courthouse and plaza. The building has a sunken first story with glass walls and the second story has few windows. The building extends outwards as it runs west.
Note: Brennan Associates acted as architect and supervisor of the numerous contractors which included Welch Construction ( concrete ), Tindall Corporation ( precast ), Manning Masonry ( masonry ), Charlotte Miscellaneous Steel ( structural steel ), Brinn Glass & Mirror, Inc. ( glass & glazing ), James L Clayton Associates, Inc. ( plumbing ),Central Heating & Air Conditioning of Kinston ( mechanical ), Melton Electric Company Inc. ( electrical ) and Hudson Brothers ( interior construction ).
New County Courthouse – Jacksonville
Location: 602 Ann Street / Old Bridge Street
Built: 2016 – 2019
Style: Modern
Architect: Smith Sinnett Architecture
Contractor: Clancy & Theys Construction Company
Description: The building faces west and is a four story red colored brick and concrete structure. The building is located on landscaped grounds to the west of the old courthouse in the center of the city. The building is tired rising to a central peak. On the roof is an octagonal cupola with silver colored dome. There are four courtrooms. The building houses the County District Court of the 4th Judicial District.
See: The 4th Judicial District includes Duplin County, Jones County and Sampson County.
History: The county was created in 1731 and New River was selected as the county seat in 1734 when the county was organized. The first courthouse was erected in 1734 on New River at the mouth of Poplar Creek. The county seat was moved to Johnston in 1741 and the second courthouse was erected in 1742. The courthouse was destroyed by storm in 1752. The third courthouse was built at Waitland’s Ferry in 1755. The courthouse was also destroyed by storm in 1786. The fourth courthouse was erected in 1786 on the lands of Edward Howard and used until 1800. The county seat was moved to Jacksonville in 1800 and the fifth courthouse was built. The sixth courthouse was built in 1885. The seventh courthouse was constructed in 1904 to 1905. The Justice Center was constructed in 2016 to 2019 at a cost of $16,400,000.
Old County Courthouse – Jacksonville
County Justice Center – Jacksonville
Photos taken 2008 an 2024