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 Oklahoma, subject matter jurisdiction refers to a court's authority to hear cases of a specific nature. This jurisdiction is determined by both the Oklahoma Constitution and statutory provisions enacted by the Oklahoma Legislature, as well as applicable federal laws and the U.S. Constitution. Oklahoma has various levels of courts, including district courts, which are the trial courts of general jurisdiction and can hear a wide range of cases, and specialized courts, such as probate, family, and small claims courts, which have jurisdiction over specific types of matters. The Oklahoma Supreme Court has appellate jurisdiction over civil matters, while the Oklahoma Court of Criminal Appeals has exclusive appellate jurisdiction over criminal cases. Federal courts, on the other hand, have jurisdiction over cases involving federal law, disputes between states, and cases involving diversity of citizenship, among other matters. It is essential for a court to have subject matter jurisdiction to render a legally enforceable judgment; otherwise, the judgment can be challenged and potentially deemed invalid.