Subject matter jurisdiction defines a court’s power to decide a lawsuit involving a particular subject matter, and to render an enforceable judgment. A court generally has jurisdiction when the particular claim raised in the case is within its constitutional jurisdiction—as provided by the state constitution or the U.S. Constitution—or because jurisdiction has been mandated by the state legislature or the United States Congress.

In Kentucky, subject matter jurisdiction refers to a court's authority to hear cases of a specific nature. The Kentucky Constitution and various statutes establish the scope of subject matter jurisdiction for different courts within the state. For instance, the Kentucky Circuit Courts are the general jurisdiction trial courts that handle civil matters over a certain dollar amount, felonies, and family law cases, among others. District Courts, on the other hand, have limited jurisdiction and typically handle misdemeanor cases, small claims, and other specific types of disputes. Federal courts, such as the U.S. District Court for the Eastern and Western Districts of Kentucky, have jurisdiction over cases involving federal law, disputes between states, and cases involving diversity of citizenship where the amount in controversy exceeds a statutory threshold. Both state and federal laws, as well as the U.S. Constitution, can confer subject matter jurisdiction, and a court must have it to lawfully decide a case and issue an enforceable judgment.