Original Jurisdiction

Original jurisdiction refers to a court's power to be the first forum to hear and decide a dispute, including determining the facts and applying the law. It stands in contrast to appellate jurisdiction, where a court reviews the legal conclusions of a lower tribunal. Most courts have one or the other; some apex courts have both.

In the United States, Article III, Section 2 of the Constitution grants the Supreme Court original jurisdiction over cases "affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party." This was famously interpreted in Marbury v. Madison (1803), where Chief Justice John Marshall held that Congress could not expand the Court's original jurisdiction beyond what Article III specifies, striking down a provision of the Judiciary Act of 1789. Today, original jurisdiction cases at the U.S. Supreme Court are rare and typically involve interstate disputes over water rights or boundaries.

In international law, the International Court of Justice (ICJ) exercises original jurisdiction over contentious cases between states that have consented to its authority, under Article 36 of its Statute. The ICJ has no appellate function. Similarly, the International Criminal Court hears cases at first instance through its Trial Chambers, with the Appeals Chamber providing review.

National variations are significant:

• India: Article 131 of the Constitution gives the Supreme Court original jurisdiction over disputes between the Union and states or between states.
• United Kingdom: The Supreme Court (established 2009) is almost entirely appellate; original jurisdiction over devolution issues is a narrow exception.
• Australia: Section 75 of the Constitution grants the High Court original jurisdiction in matters involving treaties, foreign states, or the Commonwealth as a party.

For Model UN delegates and IR researchers, the concept matters when drafting resolutions referencing judicial bodies: invoking the ICJ's original jurisdiction requires state consent, while referring a situation to the ICC requires meeting the Rome Statute's jurisdictional triggers.