The Supreme Court of Canada (SCC; French: Cour suprême du Canada, CSC) is the highest court in the judicial system of Canada. It comprises nine justices, whose decisions are the ultimate application of Canadian law, and grants permission to between 40 and 75 litigants each year to appeal decisions rendered by provincial, territorial and federal appellate courts. The Supreme Court is bijural, hearing cases from two major legal traditions (common law and civil law) and bilingual, hearing cases in both official languages of Canada (English and French).
The effects of any judicial decision on the common law, on the interpretation of statutes, or on any other application of law, can, in effect, be nullified by legislation, unless the particular decision of the court in question involves application of the Canadian Constitution, in which case, the decision (in most cases) is completely binding on the legislative branch. This is especially true of decisions which touch upon the Canadian Charter of Rights and Freedoms, which cannot be altered by the legislative branch unless the decision is overridden pursuant to section 33 (the "notwithstanding clause").
The authority to establish a national appeal court dated back to the creation of the Province of Canada in 1840, but the power remained unused. When the British North America Act, 1867, was finalized, section 101 provided Parliament may create a general court of appeal. Prime Minister John A. Macdonald introduced two bills to establish the supreme court in 1869 and 1870, however, both were withdrawn.
During the 1874 federal election, Alexander Mackenzie's Liberals included the creation of a central court of appeal as part of their campaign platform. Minister of Justice Télésphore Fournier introduced The Supreme and Exchequer Court Act, which passed on April 8, 1875, with bipartisan support. The Act simultaneously established both the Supreme Court and the Exchequer Court.
However, prior to 1949, the Supreme Court did not constitute the court of last resort as litigants could appeal the Court's decisions to the Judicial Committee of the Privy Council in London. Some cases could bypass the Supreme Court and go directly to the Judicial Committee from the provincial courts of appeal. The Supreme Court formally became the court of last resort for criminal appeals in 1933 and for all other appeals in 1949. Cases that were begun prior to those dates remained appealable to the Judicial Committee, and the last case on appeal from the Supreme Court was not decided until 1959.
The increase in the importance of the Supreme Court was mirrored by the numbers of its members. When the Court was established in 1875, it operated with a panel of six judges, with a quorum of four. This meant if there was an equal division (3–3), the appeal would be dismissed. In 1927, Parliament amended the Supreme Court Act to add a seventh position on the Court and to establish a mandatory retirement age of 75. In 1949, the bench reached its current composition of nine justices.
Prior to 1949, most of the appointees to the Supreme Court owed their position to political patronage. Each judge had strong ties to the party in power at the time of their appointment. In 1973, the appointment of a constitutional law professor Bora Laskin as chief justice represented a major turning point for the court. Laskin's federalist and liberal views were shared by Prime Minister Pierre Trudeau, who recommended Laskin's appointment to the Supreme Court, but from that appointment onward appointees increasingly either came from academic backgrounds or were well-respected practitioners with several years' experience in appellate courts.
The Constitution Act, 1982, greatly expanded the role of the Supreme Court in Canadian society by the addition of the Canadian Charter of Rights and Freedoms, which greatly broadened the scope of judicial review. The evolution from the court under Chief Justice Brian Dickson (1984–1990) through to that of Antonio Lamer (1990–2000) witnessed a continuing vigour in the protection of civil liberties. Lamer's criminal law background proved an influence on the number of criminal cases heard by the Court during his time as chief justice. Nonetheless, the Lamer court was more conservative with Charter rights, with only about a 1% success rate for Charter claimants.
Lamer was succeeded as the chief justice by Beverley McLachlin in January 2000. She was the first woman to hold that position. McLachlin's appointment resulted in a more centrist and unified court. Dissenting and concurring reasons were fewer than during the Dickson and Lamer courts. With the 2005 appointments of puisne justices Louise Charron and Rosalie Abella, the Supreme Court became the world's most gender-balanced national high court with four of its nine members being female. Justice Marie Deschamps's retirement on 7 August 2012 caused the number to fall to three; however, the appointment of Suzanne Côté on 1 December 2014 restored the number to four. The appointment of Mary T. Moreau on 6 November 2023 created the first female-majority in the history of the Court. After serving on the court for 28 years, 259 days (17 years, 341 days as chief justice), McLachlin retired in December 2017. Her successor as the chief justice is Richard Wagner.
Along with the German Federal Constitutional Court and the European Court of Human Rights, the Supreme Court of Canada is among the most frequently cited courts in the world.
The structure of the Canadian court system is pyramidal, a broad base being formed by the various provincial and territorial courts whose judges are appointed by the provincial or territorial governments. At the next level are the provincial and territorial superior trial courts, where judges are appointed by the federal government. Judgments from the superior courts may be appealed to a still higher level, the provincial or territorial superior courts of appeal.
Several federal courts also exist: the Tax Court, the Federal Court, the Federal Court of Appeal, and the Court Martial Appeal Court. Unlike the provincial superior courts, which exercise inherent or general jurisdiction, the jurisdiction of federal courts and provincially appointed provincial courts are limited by statute. In all, there are over 1,000 federally appointed judges at various levels across Canada.
The Supreme Court rests at the apex of the judicial pyramid. This institution hears appeals from the provincial courts of last resort, usually the provincial or territorial courts of appeal, and the Federal Court of Appeal. In some matters appeals come straight from the trial courts, as in the case of publication bans and other orders that are otherwise not appealable.
In most cases, permission to appeal must first be obtained from the court. Motions for leave to appeal to the court are generally heard by a panel of three of its judges and a simple majority is determinative. By convention, this panel never explains why it grants or refuses leave in any particular case, but the court typically hears cases of national importance or where the case allows it to settle an important issue of law. Leave is rarely granted, meaning that for most litigants, provincial courts of appeal are courts of last resort. But leave to appeal is not required for some cases, primarily indictable criminal cases in which at least one appellate judge (on the relevant provincial court of appeal) dissented on a point of law, and appeals from provincial reference cases.
A final source of cases is the power of the federal government to submit reference cases. In such cases, the Supreme Court is required to give an opinion on questions referred to it by the Governor in Council (the Cabinet). However, in many cases, including the most recent same-sex marriage reference, the Supreme Court has declined to answer a question from the Cabinet. In that case, the court said it would not decide if same-sex marriages were required by the Charter of Rights and Freedoms, because the government had announced it would change the law regardless of its opinion, and subsequently did.