The Canadian Charter of Rights and Freedoms, added by the passage of the 1982 Constitution Act to the country's constitution, guarantees to citizens “fundamental freedoms,” such as those of conscience and the press; “democratic rights” to vote and seek election; “mobility,” “legal,” and “equality” rights to move throughout Canada, to enjoy security of person, and to combat discrimination; and the equality of the French and English languages. The charter changed the Canadian political system by enhancing the power of the courts to make or unmake laws through judicial decisions. It also contains the so-called “notwithstanding” clause, which allows Parliament or the provincial legislatures to designate an act operative even though it might clash with a charter provision. Although the constitution and charter apply uniformly throughout Canada, the province of QuКbec has never formally signed the agreement.

The head of state of Canada is the sovereign of Great Britain. In theory, the head of the national government is the governor-general, who represents the British monarch; the actual head of government, however, is the prime minister, who is responsible to Parliament.

The central government of Canada exercises all powers not specifically assigned to the provinces; it has exclusive jurisdiction over administration of the public debt, currency and coinage, taxation for general purposes, organization of national defense, fiscal matters, banking, fisheries, commerce, navigation and shipping, energy policy, agriculture, postal service, census, statistics, patents, copyright, naturalization, aliens, indigenous peoples affairs, marriage, and divorce. Among the powers assigned to the provincial governments are education, hospitals, provincial property and civil rights, taxation for local purposes, the regulation of local commerce, and the borrowing of money. With respect to certain matters, such as immigration, the federal and provincial governments possess concurrent jurisdiction.

The nominal head of the government is the governor-general, the representative of the British crown, who is appointed by the reigning monarch on the recommendation of the prime minister of Canada. The governor-general adheres to the advice of the majority in the House of Commons (the lower chamber of the legislature) in appointing the prime minister, who is the effective head of government, and follows the prime minister's wishes in appointing the Cabinet. The Cabinet consists of as many as 40 members, most of whom are ministers presiding over departments of the federal government. The cabinet has no formal legal power but submits its decisions to Parliament.

The Canadian Parliament consists of two houses, the Senate and the House of Commons. Senators are appointed by the governor-general on the advice of the prime minister to terms that last until the age of 75; there are normally 104 senators (6 from Newfoundland; 10 each from Nova Scotia and New Brunswick; 4 from Prince Edward Island; 24 each from QuКbec and Ontario; 6 from Manitoba, Saskatchewan, Alberta, and British Columbia; and 1 each from the Northwest Territories and Yukon Territory). In 1990 the Conservative federal government found that proposed legislation was being held up by the Liberal-controlled Senate. Invoking a measure in Canada's consitution that had never been used before, Prime Minister Brian Mulroney added 8 new senators, thereby increasing the total number of senators to 112 and achieving a Conservative majority. The number of senators has since returned to 104.

Members of the House of Commons are elected in 295 federal electoral districts whose boundaries are periodically adjusted to reflect population growth or redistribution. Each district contains, on average, about 100,000 constituents. Federal elections are held at the prime minister's discretion, but must be called within a five-year period; in practice, they are called about every four years. Laws are first debated in the House of Commons, but must also be approved by the Senate and signed by the governor-general before coming into effect. The prime minister is the leader of the majority party in the House of Commons; if no majority exists, the party with the most seats in Parliament leads a “minority government.”

The government of each of Canada's ten provinces is in theory headed by a lieutenant governor, who represents the sovereign of Great Britain and is appointed by the governor-general on the advice of the federal prime minister. Like the governor-general, however, the lieutenant governor has little actual power, and in practice the chief executive of each province is the premier, who is responsible to a unicameral provincial legislature. Yukon Territory and the Northwest Territories are both governed by federally appointed commissioners, assisted in the Northwest Territories by a legislative assembly and in Yukon Territory by an elected council and legislature. A third territory, Nunavut, will be formally created in 1999 and will have a similar governmental makeup to the other two territories.

The strongest national political parties in Canada during the 20th century traditionally have been the Liberal Party and the Progressive Conservative Party, also known as Tories. However, a voter backlash in the early 1990s has resulted in great upheaval in the Canadian political picture, and established groups such as these two parties have lost much of their powers. Although they agree on many issues, the Liberals have generally supported government intervention to promote the general welfare, while the Conservatives have favored free enterprise and the limited state. The smaller New Democratic Party, by contrast, endorsed social democracy and the rights of organized labor, and found support in Ontario and the western provinces. The new Alberta-based Reform Party has become an increasingly significant vehicle of conservative sentiment in English Canada, outside the Maritime provinces. The Bloc QuКbКcois, a splinter from the Conservatives, has risen in prominence by espousing QuКbec sovereignty. To a degree, this party acts as the federal arm of the Parti QuКbКcois, a QuКbec-based party that held power in the province from 1976 to 1985.

All levels of government share the responsibility for social welfare in Canada. The federal government administers comprehensive income-maintenance measures, such as the Canada Pension Plan, Canada Assistance Plan, old-age security pensions, family allowances, youth allowances, and unemployment insurance, in which nationwide coordination is necessary. The federal government gives aid to the provinces in meeting the costs of public assistance; it also provides services for special groups, such as Native Americans, veterans, and immigrants. Administration of welfare services is mainly the responsibility of the provinces, but local authorities, generally with financial aid from the province, often assume the provision of services. Provincial governments have the major responsibility for education and health services in Canada, with municipalities also assuming authority over matters delegated to them by provincial legislation. Health and Welfare Canada is the chief federal agency in health matters.

The Medical Care Act, passed in 1966, has permitted the federal government to contribute about half the cost of the Medical Care Insurance Program (Medicare), with the respective province contributing the remainder. The program establishes the following minimum criteria: (1) comprehensive coverage, to cover all medically required services rendered by physicians and surgeons; (2) universal availability to all residents; (3) portability, to cover temporary or permanent change in residence to another province; and (4) nonprofit basis.