The U.S. Supreme Court has original jurisdiction mainly in cases involving states as parties or foreign diplomatic officials, and this jurisdiction is partly exclusive and partly shared with lower courts.

Core rule from the Constitution

Article III, Section 2 of the U.S. Constitution gives the Supreme Court original (first‑instance) jurisdiction in:

  • “All cases affecting ambassadors, other public ministers and consuls.”
  • “Those in which a state shall be party.”

This means certain disputes can start in the Supreme Court instead of being appealed up from a lower court.

How federal law defines the categories

Federal statute 28 U.S.C. § 1251 breaks this down into exclusive and non‑exclusive original jurisdiction:

  • Exclusive original jurisdiction (only the Supreme Court can hear these):
    • “All controversies between two or more States.”
* Typical examples: state‑versus‑state boundary or water‑rights disputes such as _Kansas v. Colorado_ and _New Jersey v. Delaware_.
  • Non‑exclusive (concurrent) original jurisdiction (Supreme Court shares with lower courts):
* Cases in which the United States sues a state.

* Cases between a state and citizens of another state, or a state and foreign citizens or subjects.

* Cases affecting ambassadors, other public ministers, consuls, and similar foreign officials.

In these non‑exclusive categories, Congress has allowed lower federal courts to hear the cases as well, except when both parties are states.

Important limits and landmark cases

  • The Court has said its original jurisdiction comes only from the Constitution and cannot be expanded by Congress.
    • This was made famous in Marbury v. Madison , where the Court invalidated a statute that tried to add to its original jurisdiction.
  • The Court interprets original jurisdiction narrowly , so such cases are rare and usually involve major issues like:
    • Interstate boundary or water disputes.
    • Significant conflicts between states and the federal government, such as United States v. Texas over land ownership.

Simple takeaway

  • The Supreme Court has original jurisdiction when:
    • A state is a party , especially in disputes between states (exclusive).
    • The case affects ambassadors or other high foreign officials (shared with lower courts).
  • In nearly all other federal questions, the Court acts in its appellate role, reviewing decisions from lower courts rather than hearing the case first.

Information gathered from public forums or data available on the internet and portrayed here.