A supreme court is the highest court within a jurisdiction.
A quintessential example of a supreme court is the Supreme Court of the United States, which is mandated by Article III Section 1 of the US Constitution. The U.S. Supreme Court holds two types of jurisdictions: original jurisdiction and appellate jurisdiction.
In many jurisdictions, the supremacy of a court is considered based on its appellate jurisdiction. The final (or highest) authority within the appellate system is considered the supreme appellate authority within the jurisdiction. Thus, the Supreme Court of the United States and the Supreme Court of Arizona, for example, are referred to as the "supreme court" within their jurisdictions because they are the final court of appeals within their jurisdictions.
In other jurisdictions, such as New York State, for example, the supremacy of a court is determined based on the broadness of its original jurisdiction. Because certain trial-level courts have unlimited original jurisdiction within the New York State court system, New York State opts to call their broadest trial-level courts supreme courts (e.g., Kings County Supreme Court in Brooklyn, NY).
[Last updated in October of 2024 by the Wex Definitions Team]