The judiciary of Jamaica is based on the judiciary of the United Kingdom. The courts are organized at four levels, with additional provision for appeal to the Judicial Committee of the Privy Council in London. The Court of Appeal is the highest appellate court. The Supreme Court has unlimited jurisdiction in all cases, and sits as the Circuit Court to try criminal cases. The Parish Court (formerly known as the Resident Magistrate's court) in each parish hears both criminal and civil cases, excluding grave offences. The Petty Sessions are held under Justices of the Peace, with power to hear minor crimes.
Jamaica is a common law jurisdiction, in which precedents from English law and British Commonwealth tradition may be taken into account.
The Court of Appeal is the highest appellate court in Jamaica; it is superior to the Supreme Court. The Court is composed of a President and six other Judges. The Chief Justice is also a judge ex officio of the Court of Appeal, but participates only when asked to do so by the President. Although the Court of Appeal is the highest court in Jamaica, its judgements may themselves be appealed to the Queen-in-Council, in which case they are heard by the Judicial Committee of the Privy Council in London.
In May 2015, the House of Representatives approved with the necessary two-thirds majority bills to end legal appeals to the Judicial Committee of the Privy Council and make the Caribbean Court of Justice as Jamaica's final court of appeal. The reform will be debated by the Senate. However, the government will need the support of at least one opposition senator for the measures to be approved by the required two-thirds majority.
The Supreme Court has unlimited original jurisdiction in criminal and civil cases. The Chief Justice of the Supreme Court is the head of the judiciary (currently Zaila McCalla). Besides the Chief Justice, the court is composed of the Senior Puisne Judge and additional Puisne Judges, with their number established by Parliament. In response to increasing case load, Parliament in 2008 increased the number of spaces on the Supreme Court from 26 to 40 with the new spaces filled over time by appointment of new judges.