What is the High Court of Australia?

The High Court of Australia is the country's highest court and the final court of appeal on all matters. It is established under Chapter III of the Australian Constitution, with original jurisdiction in matters specified in the Constitution and appellate jurisdiction from all other Australian courts. The High Court has played a central role in shaping Australian constitutional law and the relationship between the Commonwealth and the states.

The Court's two main functions are interpreting the Constitution and hearing final appeals. As the interpreter of the Constitution, the High Court decides whether federal and state laws are within the constitutional powers of the relevant Parliament, whether executive action is constitutional, and how the Constitution applies to new situations. Major decisions including Engineers Case (1920), Communist Party Case (1951), Mabo (1992), Wik (1996), the implied freedom of political communication cases (1992 onwards), and the dual citizenship cases (2017 to 2018) have shaped the constitutional system fundamentally.

As the final court of appeal, the High Court hears appeals from state and territory supreme courts, the Federal Court, and the Federal Circuit and Family Court. Most appeals require special leave from the High Court itself, granted only where the case raises a matter of public importance, a substantial miscarriage of justice, or a question of law that requires authoritative settlement. About 200 to 250 special leave applications are filed each year, with about 50 granted. The Court hears about 50 to 70 substantive appeals a year.

The High Court sits in Canberra in a purpose-built building opened in 1980. It also conducts sittings occasionally in state capitals. Hearings are public, with the Full Court (the entire bench of seven Justices) hearing major constitutional cases and benches of five or seven hearing other matters. The Chief Justice presides over the Court, with the current Chief Justice being Stephen Gageler, who succeeded Susan Kiefel in November 2023. The High Court's decisions are binding on all Australian courts and on all Australian governments, with the only recourse being constitutional amendment under section 128 of the Constitution.