The Canadian legal system has its foundation in the British common law system, inherited from being a former colony of the United Kingdom and later a member of the Commonwealth of Nations. Quebec, however, still retains a civil system for issues of private law. Both legal systems are subject to the Constitution of Canada.

Canada's constitution is its supreme law, and any law passed by any federal, provincial, or territorial government that is inconsistent with the constitution is invalid.

The Constitution Act, 1982 stipulates that Canada's constitution includes that act, a series of thirty acts and orders referred to in a schedule to that act (the most notable of which is the Constitution Act, 1867), and any amendment to any of those acts. However, the Supreme Court of Canada has found that this list is not intended to be exhaustive, and in 1998's Reference re Secession of Quebec identified four "supporting principles and rules" that are included as unwritten elements of the constitution: federalism, democracy, constitutionalism and the rule of law, and respect for minorities. While these principles are an enforceable part of Canada's constitution, Canadian courts have not used them to override the written text of the constitution, instead confining their role to "filling gaps".

Canada ( /ˈkænədə/) is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean. Spanning over 9,900,000 km² (3,800,000 sq mi), Canada is the world's second-largest country by total area, and its common border with the United States is the longest land border in the world.

The land that is now Canada has been inhabited for millennia by various Aboriginal peoples. Beginning in the late 15th century, British and French colonial expeditions explored, and later settled, along the region's Atlantic coast. France ceded nearly all of its colonies in North America in 1763 after the Seven Years' War. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces. This began an accretion of provinces and territories and a process of increasing autonomy; the Canada Act 1982 severed the vestiges of legal dependence on Britain.