The Whangarei Supreme Court was established in 1937. The Whangarei Supreme Court Registrar was appointed under statutory authority and was responsible for the functions of the Court. These included the hearing of criminal proceedings, civil actions, miscellaneous proceedings, and admiralty proceedings. The Court also confirmed the authority of executors in the form of Probate documents, and administered applications for Decree Absolutes until 1980 when the Family Court was established.
In the absence of an Official Assignee's Office in Whangarei, the Court carried out the functions of the Insolvency and Trustee Service for bankrupts and liquidated companies in the region.
The High Court was located in the same building as the District Court, and shared the same staff.