All provinces and territories within Canada, excluding Quebec, follow the common law legal tradition.  Equally, courts have power under the provincial Judicature Acts to apply equity.

As with all common law countries, Canadian law adheres to the doctrine of stare decisis.  Lower courts must follow the decisions of higher courts by which they are bound. For instance, all Ontario lower courts are bound by the decisions of the Ontario Court of Appeal and, all British Columbia lower courts are bound by the decisions of the British Columbia Court of Appeal. However, no Ontario court is bound by decisions of any British Columbia court and no British Columbia court is bound by decisions of any Ontario court. Nonetheless, decisions made by a province’s highest court (provincial Courts of Appeal) are often considered as “persuasive” even though they are not binding on other provinces.

Only the Supreme Court of Canada has authority to bind all courts in the country with a single ruling.  The busier courts, such as the Court of Appeal for Ontario, for example, are often looked to for guidance on many local matters of law outside the province, especially in matters such as evidence and criminal law.

When there is little or no existing Canadian decision on a particular legal issue and it becomes necessary to look to a non-Canadian legal authority for reference, decisions of English courts and American courts are often utilized.  In light of the long-standing history between English law and Canadian law, the English Court of Appeal and the House of Lords are often cited as and considered persuasive authority, and are often followed.  If the legal question at issue relates to matters of constitutional or privacy law, however, decisions of United States courts are more likely to be utilized by Canadian lawyers because there is a much greater body of jurisprudence in U.S. law than English law in these areas.

Decisions from Commonwealth nations, aside from England, are also often treated as persuasive sources of law in Canada.

A major difference between U.S. and Canadian common law is that Canada does not follow the doctrine of Erie Railroad Co. v. Tompkins (1938), and this is so taken for granted that the Supreme Court of Canada has never needed to actually rule upon the question.  In other words, there is no distinction in Canada between federal and provincial common law, and the Supreme Court can and does dictate common law directly to the provinces on all matters traditionally encompassed by common law (to the extent not superseded by legislation).  From the American perspective, Canadian federalism is thus relatively incomplete, since Canada continues to operate as a unitary state with respect to common law (and is truly federal only as to statutory law).

Due to Canada’s historical connection with the United Kingdom, decisions of the House of Lords before 1867 are technically still binding on Canada unless they have been overturned by the Supreme Court of Canada, and Canada is still bound by the decisions of the Privy Council before the abolishment of appeals to that entity in 1949.  In practice, however, no court in Canada has declared itself bound by any English court decision for decades, and it is highly unlikely that any Canadian court will do so in the future.

Criminal offences are found only within the Criminal Code and other federal statutes; an exception is that contempt of court is the only remaining common law offence in Canada.

( Source wikipedia )