Common law in Canada is the legal system built from accumulated court decisions rather than a single written code, and it governs private legal matters in every province and territory except Quebec. It came from the English legal tradition, has been shaped by Canadian courts and legislatures for well over a century, and operates under the Constitution alongside statutes passed by Parliament and the provinces.
What Common Law Actually Is
Common law develops case by case. When a court decides a legal question, that decision becomes part of a body of law future courts draw on when similar disputes come up. Over centuries, those rulings accumulate into detailed rules covering contracts, property, personal injury, and much of everyday private law. Because the law grows through decisions rather than a single comprehensive code, it can adapt to new situations without waiting for a legislature to act.
This is why common law is sometimes called judge-made law or case law. But statutes matter too. When Parliament or a provincial legislature passes a law, it takes priority over any common law rule on the same subject.1Department of Justice Canada. About Canada’s System of Justice Common law fills the gaps where no statute exists and gives courts the interpretive framework they use to apply statutes to real facts.
How Precedent Binds Courts
The doctrine that makes common law function is stare decisis, roughly “stand by what has been decided.” When a court resolves a legal issue, other courts facing the same issue are expected to follow it. That is how similar cases end up with similar outcomes and how people can predict what a court will do with their situation.
Not every line in a judgment carries equal weight. The part that binds future courts is the legal reasoning the judge needed to reach the result, often called the ratio. Comments a judge makes that weren’t strictly necessary to the outcome are persuasive but not binding. The Supreme Court of Canada has recognized this sits on a spectrum: the further a remark drifts from the core reasoning, the less authority it carries. Lawyers argue constantly about which side of that line a particular statement falls on, because the answer decides whether a lower court has to follow it.
Canada’s Court Hierarchy
Precedent works only because courts are ranked. A decision from a higher court binds every court below it in the same jurisdiction. A ruling from a court at the same level, or from a different province, can influence a judge but doesn’t compel a particular result.2Department of Justice Canada. The Judicial Structure
At the top is the Supreme Court of Canada. Its nine justices hear appeals from every province and territory, and their decisions are final. When the Supreme Court rules on a point of common law, every court in the country must follow it.2Department of Justice Canada. The Judicial Structure Below it, each province has its own appeal court whose rulings bind the trial courts in that province. A trial judge in Alberta is bound by the Alberta Court of Appeal but only influenced by what the Ontario Court of Appeal has said on the same question.
There is also a federal layer. The Federal Court and the Federal Court of Appeal handle matters that fall to federal jurisdiction, and their decisions are ultimately reviewable by the Supreme Court of Canada.2Department of Justice Canada. The Judicial Structure
Why Quebec Is Different
Canada operates two legal traditions at once. Nine provinces and the three territories use common law for private matters. Quebec uses a civil law system descended from the French legal tradition and now set out in the Civil Code of Quebec, which replaced the earlier Civil Code of Lower Canada in 1994.3Parks Canada. Civil Code and Common Law2Department of Justice Canada. The Judicial Structure
The practical difference is where a judge looks first. In common law provinces, a judge working through a contract dispute reads prior decisions dealing with similar facts. In Quebec, the judge starts with the Civil Code’s written provisions and uses past decisions mainly for consistency rather than as binding authority. Both systems sit under the same federal framework. Federal legislation, including the Criminal Code, applies across every province and territory regardless of which private-law tradition they follow.4Department of Justice Canada. Criminal Code (RSC 1985, c C-46)
How the Constitution Sits Above Common Law
The Constitution of Canada is the supreme law of the country. Any law, whether a statute or a common law rule, that conflicts with the Constitution is invalid to the extent of that conflict.5Department of Justice Canada. Charterpedia – Section 52(1) of the Constitution Act 1982 It sets the outer limits within which common law and statutes both have to operate.
Two parts of the Constitution matter most here. The Constitution Act, 1867 divides legislative power between Parliament and the provinces. Parliament has exclusive authority over things like criminal law, banking, marriage and divorce, and trade regulation. The provinces control property and civil rights, health care, education, and local matters.6Department of Justice Canada. The Constitution Acts 1867 to 1982 That is why criminal law is the same across the country while contract and property rules can differ from one province to the next.
The Canadian Charter of Rights and Freedoms, part of the Constitution Act, 1982, has reshaped common law since it was adopted. Courts are expected to develop common law principles in a way that reflects Charter values like equality, freedom of expression, and the right to life and security of the person. When a common law rule conflicts with a Charter right, courts can and do modify the rule. The Charter has driven some of the largest shifts in Canadian common law over the past four decades, especially in privacy, search and seizure, and discrimination.
Indigenous Legal Traditions
Common law and civil law aren’t the whole picture. Indigenous peoples maintained their own legal orders long before European contact, and those traditions have not disappeared. Section 35 of the Constitution Act, 1982 recognizes and affirms the existing Aboriginal and treaty rights of First Nations, Inuit, and Métis peoples.7Government of Canada. Section 35 of the Constitution Act 1982 – Background Those constitutionally protected rights can include land title, hunting and fishing rights, self-government rights, and cultural and social rights, and they vary from group to group based on distinct customs and practices.
In 2021, Parliament passed the United Nations Declaration on the Rights of Indigenous Peoples Act, which affirmed the UN Declaration as a tool for interpreting and applying Canadian law and committed the federal government to bringing federal laws into line with the Declaration’s standards.8Department of Justice Canada. Backgrounder: United Nations Declaration on the Rights of Indigenous Peoples Act Its full effect on day-to-day legal practice is still working itself out.
How Common Law Changes Over Time
Common law is not frozen. It changes in two main ways.
Judges change it. When a higher court runs into a situation existing precedent doesn’t cover cleanly, it can extend or adapt established principles. Judges do this routinely by distinguishing the facts of the current case from a prior one, reaching a different result without formally overruling the earlier decision. Less often, a higher court overrules its own past ruling outright. The Supreme Court of Canada has said the threshold for that is high: it weighs getting the law right against the value of certainty, and it requires compelling reasons before departing from an established rule. Disagreement with a prior decision isn’t enough on its own.
Legislatures also change it. Parliament and the provincial legislatures can pass statutes that codify common law principles, modify them, or replace them entirely. When a statute covers ground previously governed by common law, the statute takes precedence.1Department of Justice Canada. About Canada’s System of Justice Much of employment law and landlord-tenant law began as common law and has since been largely replaced by provincial statutes. The common law doesn’t disappear when a statute arrives; it fills the gaps the statute leaves and provides the background courts use when statutory language is ambiguous.
A Note on Common-Law Relationships
Many people searching this phrase are looking for something different: common-law partnerships. In everyday use, “common-law” describes a couple living together in a conjugal relationship without being married. Canadian law recognizes these relationships for many purposes, but the rules vary depending on whether you’re dealing with federal law, provincial law, immigration, or tax.
For federal immigration, a common-law partner is someone who has lived with you continuously for at least 12 consecutive months in a conjugal relationship, with only short temporary separations for reasons like work or family obligations.9Immigration, Refugees and Citizenship Canada. For My Spousal Sponsorship Application, What Is a Common-Law Partner The federal Income Tax Act uses a similar 12-month threshold. Provincial family law definitions can differ. Some provinces extend property-division rights to common-law partners after a set period; others do not give common-law partners the automatic rights married spouses have. Rules around spousal support, inheritance, and pensions also vary by province.
Being in a common-law relationship does not automatically give you the same legal rights as marriage. What you’re entitled to depends on the province you live in and the area of law involved. If you’re in or entering a long-term relationship without a formal marriage, look into your province’s specific rules on property and support before assuming anything.