William Lyon Mackenzie advocated the creation of a Canadian republic during the 1837 Upper Canada Rebellion and, after the defeat of his uprising in Toronto, established a provisional government for the Republic of Canada on Navy Island. The Patriotes Rebellion in Lower Canada is also thought to have been republican in nature. (see also Rebellions of 1837). The British government's Durham Report in the aftermath of the rebellions led to the introduction of responsible government thus quelling republican sentiment by giving settlers in what became the United Province of Canada more rights while retaining British rule and eventually leading to Canadian confederation.

Latent republican sentiment remained a factor in Quebec where Henri Bourassa and other nationalists opposed British imperialism and advocated Canadian independence from the British Empire in response to the Boer War and, later, the Conscription Crisis of 1917 during the First World War. Republican sentiment became more prominent with the rise of the Quebec nationalist movement in the 1960s with the demands for an independent republic of Quebec put forward by both the Front de libération du Québec which advocated violent methods and the parliamentary Quebec indépendentistes who formed the Parti Québécois. Queen Elizabeth's royal visit to Quebec City in 1964 provoked a militant anti-monarchist and Quebec nationalist demonstration which was put down by police with 36 arrests and scores of injuries in what is remembered as samedi de la matraque (truncheon Saturday). Support for the monarchy remains weakest in Quebec to this day.

Simultaneously, the idea of a Canadian republic where the Queen would be replaced by an elected head of state gathered strength in English Canada among those who saw the abandonment of what was seen as the vestiges of colonialism as both a means of stengthening national unity between English and French_Canadians and as a means of asserting Canadian sovereignty and nationhood. The Toronto Star, English Canada's largest circulation daily newspaper first endorsed the creation of a Canadian republic during the Canadian centennial year of 1967. While the idea of a republic was a minor issue during the Canadian Constitutional negotiations of the 1970s, when a new Constitution was agreed to in 1982 it included a provision requiring unanimous consent of the federal government and all ten provincial governemnts before any change could be implemented to the status of the monarchy. This was agreed to by Prime Minister Pierre Trudeau as a concession to his two closest allies among the provincial premiers, William Davis and Richard Hatfield, both of whom were fervent monarchists. As a result it is constitutionally more difficult to remove the monarchy in Canada than it is in any other Commonwealth realm including the United Kingdom. Nevertheless, support for a republic has grown in Canada in recent years with senior Canadian Cabinet ministers such as John Manley and Brian Tobin expressing their republican views while serving in the government of Jean Chrétien and the influential Globe and Mail newspaper adopting a pro_republican editorial position in the 1990s.

Public opinion polls in Canada show that the overwhelming sentiment concerning the monarchy to be apathy and indifference. Some polls have shown a slight majority of Canadians to favour the creation of a republic but most polls suggest that the issue is a low priority among Canadians. Monarchists, traditionally, are more passionate about their advocacy for the monarchy than republicans have been in their opposition. While the Monarchist League of Canada was formed in 1970 to fight what it saw as "creeping republicanism" in the gradual removal of references to royalty and the dominion by federal institutions, it was only in 2002 that republicans formed their own lobby group, Citizens for a Canadian Republic.

See also: Monarchy in Canada - republicanism debate