The Government of Canada introduces the Civil Marriage Act. This legislation would become law on July 20, 2005, legalizing same-sex marriage.

The Civil Marriage Act is a federal statute legalizing same-sex marriage across Canada. At the time it became law, same-sex marriage had already been legalized by court decisions in all Canadian jurisdictions except Alberta, Prince Edward Island, the Northwest Territories, and Nunavut.

It was introduced as Bill C-38 in the first session of the 38th Canadian Parliament on February 1, 2005. It passed the House of Commons on June 28, 2005, and the Senate on July 19, 2005. The Act became law when it received Royal Assent on July 20, 2005.

As with all federal legislation in Canada, the Act is written in both French and English. Both versions have equal authority. The French title is Loi sur le mariage civil.

The government of Canada (French: gouvernement du Canada) is the body responsible for the federal administration of Canada. A constitutional monarchy, the Crown is the corporation sole, assuming distinct roles: the executive, as the Crown-in-Council; the legislature, as the Crown-in-Parliament; and the courts, as the Crown-on-the-Bench. Three institutions—the Privy Council (conventionally, the Cabinet); the Parliament of Canada; and the judiciary, respectively—exercise the powers of the Crown.

The term Government of Canada (French: Gouvernement du Canada) can refer to either the collective set of all three institutions, or more specifically to the executive—ministers of the Crown (the Cabinet) and the federal civil service (whom the Cabinet direct)—which corporately brands itself as the Government of Canada, or more formally, Her Majesty's Government (French: Gouvernement de Sa Majesté).In both senses, the current construct was established at Confederation through the Constitution Act, 1867—as a federal constitutional monarchy, wherein the Canadian Crown acts as the core, or "the most basic building block", of its Westminster-style parliamentary democracy. The Crown is thus the foundation of the executive, legislative, and judicial branches of Canadian government. The monarch, Queen Elizabeth II, is personally represented by a governor general (currently Mary Simon) and is head of state. A prime minister (currently Justin Trudeau) is the head of government who is invited by the Crown to form a government after securing the confidence of the House of Commons, which is typically determined through the election of enough members of a single political party in a federal election to provide a majority of seats in Parliament, forming a governing party. Further elements of governance are outlined in the rest of the Canadian Constitution, which includes written statutes in addition to court rulings, and unwritten conventions developed over centuries.Constitutionally, the Queen's Privy Council for Canada is the body that advises the sovereign or their representative on the exercise of executive power. This task is nearly exclusively carried out by a committee within the Queen's Privy Council known as the Cabinet who collectively set the government's policies and priorities for the country. It is composed of ministers of the Crown and is chaired by the prime minister. The sovereign appoints the members of Cabinet on the advice of the prime minister who, by convention, are selected from the House of Commons or, less often, the Senate. During its term, the government must retain the confidence of the House of Commons, and certain important motions, such as the passing of the government's budget, are considered as confidence motions. Laws are formed by the passage of bills through Parliament, which are either sponsored by the government or individual members of Parliament. Once a bill has been approved by both the House of Commons and the Senate, royal assent is required to make the bill become law. The laws are then the responsibility of the government to oversee and enforce.