In other words, it possesses no original jurisdiction—it does not deal with trials of matters coming before the court for the first time.

The Court of Appeal is required, however, to abide by decisions of the Constitution of the Republic of Singapore Tribunal in certain situations.

[6][7] All courts ceased to function during World War II when the Japanese occupation of Singapore began in February 1942.

There was no change in the judicial system when the Straits Settlements were dissolved in 1946 and Singapore became a crown colony in its own right,[8] except that the Supreme Court of the Straits Settlements became known as the Supreme Court of Singapore.

[9] Singapore ceased to be part of the British Empire in 1963 when it joined the Federation of Malaysia.

In turn, the Judicial Committee conveyed their recommendations on appeals to the Yang di-Pertuan Agong, who then made the final orders.

At the time of the nation's full independence, no changes were made to the judicial system.

[12] The Judicial Committee Act 1966[13] was passed to enable the Privy Council to continue its role as Singapore's final court of appeal, and to remove the need to petition the British monarch or the Yang di-Pertuan Agong in order to appeal.

[16] Moves towards full legal autochthony from Britain began in 1989, when appeals to the Privy Council were limited[17] in the wake of a 1988 Privy Council ruling[18] reversing the Court of Appeal's decision to strike opposition politician J.B. Jeyaretnam off the roll of advocates and solicitors for having been convicted of cheque fraud and making a false declaration concerning the accounts of the Workers' Party of Singapore.

[19] The Privy Council judged Jeyaretnam to have been the victim of a "grievous injustice" in Singapore's courts, having been "fined, imprisoned and publicly disgraced for offences of which [he and his co-accused] were not guilty".

The most recent case of sitting with 5 justices was the 2022 decision How Weng Fan and others v Sengkang Town Council and other appeals.

[29] The Court may also sit with just two Judges of Appeal in appeals in civil matters against interlocutory orders and other orders apart from judgments handed down after trials commenced by writs of summons or hearings commenced by other originating processes such as originating summons.

These include cases where the amount or value of the subject-matter at the trial was S$250,000 or less,[41] and High Court appeals concerning the adoption of children, the making of protection orders to prevent family violence, and maintenance for wives and children.

It will not act in this manner on the basis of immaterial errors, defects or irregularities that do not affect the merits of the case or the jurisdiction of the High Court.

[55] The Court is entitled to summarily reject an appeal if the grounds of appeal do not involve any question of law, the conviction is supportable by the evidence, and there is nothing in the circumstances of the case which raises a reasonable doubt as to whether the conviction was right or leads the Court to think the sentence should be reduced.

[60] A trial court's judgment, sentence or order may only be reversed or set aside if it was legally incorrect or against the weight of the evidence.

[63] In the 2009 decision Yong Vui Kong v. Public Prosecutor,[64] the Court left open the issue of whether it had inherent jurisdiction following the conclusion of an appeal to reopen the matter if new evidence came to light.

It expressed the view that "it would be in the interest of justice that the court should have the power to correct the mistake, rather than rely on the Executive to correct what is essentially an error in the judicial process", and that it is "reasonable to assume that the court is better placed to evaluate the merits of the new evidence than the Executive".

[65] In earlier cases the view had been taken that in the interests of finality, after delivering its judgment in an appeal the Court should be regarded as functus officio, that is, it has fully "performed its office" and no longer has any legal power to act.

However, in Yong Vui Kong the Court said:[66] [T]he finality principle should not be applied strictly in criminal cases where the life or liberty of the accused is at stake as it would subvert the true value of the judicial process, which is to ensure, as far as possible, that the guilty are convicted and the innocent are acquitted.

On 11 July that year, the Court handed down a practice statement declaring that it would regard itself free to depart from previous decisions of its own or of the Privy Council[75] in any case where adherence to such prior decisions would cause injustice in a particular case or constrain the development of the law in conformity with the circumstances of Singapore.

Bearing in mind the danger of retrospectively disturbing contractual, proprietary and other legal rights, this power will be exercised sparingly.The Court justified this new principle on the basis that "the political, social and economic circumstances of Singapore have changed enormously since Singapore became an independent and sovereign republic.

The development of our law should reflect these changes and the fundamental values of Singapore society.