An appellate court, commonly called an appeals court, court of appeals (American English),^[1] appeal court (British English), court of second instance or second instance court, is any court of law that is empowered to hear an appeal of a trial court or other lower tribunal. In most jurisdictions, the court system is divided into at least three levels: the trial court, which initially hears cases and reviews evidence and testimony to determine the facts of the case; at least one intermediate appellate court; and a supreme court (or court of last resort) which primarily reviews the decisions of the intermediate courts. A jurisdiction's supreme court is that jurisdiction's highest appellate court.^[2] Appellate courts nationwide can operate under varying rules.^[3]

The authority of appellate courts to review the decisions of lower courts varies widely from one jurisdiction to another. In some areas, the appellate court has limited powers of review. Generally, an appellate court's judgment provides the final directive of the appeals courts as to the matter appealed, setting out with specificity the court's determination that the action appealed from should be affirmed, reversed, remanded or modified.^[4]

While many appellate courts have jurisdiction over all cases decided by lower courts, some systems have appellate courts divided by the type of jurisdiction they exercise. Some jurisdictions have specialized appellate courts, such as the Texas Court of Criminal Appeals, which only hears appeals raised in criminal cases, and the U.S. Court of Appeals for the Federal Circuit, which has general jurisdiction but derives most of its caseload from patent cases, on one hand, and appeals from the Court of Federal Claims on the other. In the United States, Alabama, Tennessee, and Oklahoma also have separate courts of criminal appeals. Texas and Oklahoma have the final determination of criminal cases vested in their respective courts of criminal appeals,^[5] while Alabama and Tennessee allow decisions of its court of criminal appeals to be finally appealed to the state supreme court.^[6][7]

Court of Criminal Appeals include:

The Court of Appeal of New Zealand, located in Wellington, is New Zealand's principal intermediate appellate court.^[8] In practice, most appeals are resolved at this intermediate appellate level, rather than in the Supreme Court.^[9]

The Court of Appeal of Sri Lanka, located in Colombo, is the second senior court in the Sri Lankan legal system.

In the United States, both state and federal appellate courts are usually restricted to examining whether the lower court made the correct legal determinations, rather than hearing direct evidence and determining what the facts of the case were.^[10] Furthermore, U.S. appellate courts are usually restricted to hearing appeals based on matters that were originally brought up before the trial court. Hence, such an appellate court will not consider an appellant's argument if it is based on a theory that is raised for the first time in the appeal.^[11]

In most U.S. states, and in U.S. federal courts, parties before the court are allowed one appeal as of right. This means that a party who is unsatisfied with the outcome of a trial may bring an appeal to contest that outcome. However, appeals may be costly, and the appellate court must find an error on the part of the court below that justifies upsetting the verdict. Therefore, only a small proportion of trial court decisions result in appeals. Some appellate courts, particularly supreme courts, have the power of discretionary review, meaning that they can decide whether they will hear an appeal brought in a particular case.

Many U.S. jurisdictions title their appellate court an court of appeal or court of appeals.^[12] Historically, others have titled their appellate court a court of errors (or court of errors and appeals), on the premise that it was intended to correct errors made by lower courts. Examples of such courts include the New Jersey Court of Errors and Appeals (which existed from 1844 to 1947), the Connecticut Supreme Court of Errors (which has been renamed the Connecticut Supreme Court), the Kentucky Court of Errors (renamed the Kentucky Supreme Court), and the Mississippi High Court of Errors and Appeals (since renamed the Supreme Court of Mississippi). In some jurisdictions, a court able to hear appeals is known as an appellate division.

The phrase "court of appeals" most often refers to intermediate appellate courts. However, the Maryland and New York systems are different. The Maryland Court of Appeals and the New York Court of Appeals are the highest appellate courts in those states. The New York Supreme Court is a trial court of general jurisdiction. Depending on the system, certain courts may serve as both trial courts and appellate courts, hearing appeals of decisions made by courts with more limited jurisdiction.