Each state’s constitution and laws establish the state’s courts, which interpret state laws (and generally not federal laws). A court of last resort, often known as a supreme court, is usually the highest court in the state. Some states also have an intermediate court of appeals. Below these intermediate courts of appeal are the state trial courts, where most lawsuits begin. State trial courts are referred to differently in different states—often as district courts, circuit courts, or superior courts.

State courts are often courts of general jurisdiction—meaning they hear all types of cases—involving criminal law, family law, probate law, and general disputes involving money and property. But more populated counties often have courts of specific jurisdiction, such as family courts that only hear family law matters (divorce, child custody, child support); criminal courts that only hear criminal matters; and probate courts that only handle the probate of estates and related litigation.

In Missouri, the judicial system is structured with a Supreme Court at its apex, serving as the court of last resort. Below the Supreme Court is the Missouri Court of Appeals, which is an intermediate appellate court divided into three districts. At the base of the hierarchy are the trial courts, known in Missouri as Circuit Courts. These Circuit Courts have general jurisdiction and handle a wide array of cases, including criminal, civil, family, and probate matters. Missouri's larger counties may have specialized divisions within the Circuit Courts, such as Family Courts for family-related issues, and Probate Courts for matters concerning wills and estates. The state's judicial system is established and governed by the Missouri Constitution and state statutes, which provide the framework for court operations, jurisdiction, and the types of cases they may hear.