Because the country contains two major language groups and numerous other linguistic minorities, in Canada official languages policy has always been an important and high-profile area of public policy.

In an exhaustive 1971 study of Canadian language law prepared for the Royal Commission on Bilingualism and Biculturalism, Claude-Armand Sheppard offered this definition for the term “official language”: “[An] official language is a language in which all or some of the public affairs of a particular definition are, or can be, conducted, either by law or custom. We take public affairs to comprise the parliamentary and legislative process, administrative regulations, the rendering of justice, all quasi-judicial activities, and the overall day-to-day administration.”Sheppard, Claude-Armand, The Law of Languages in Canada. Studies of the Royal Commission on Bilingualism and Biculturalism, no. 11. Ottawa: Information Canada, 1971, p. 291.

This article lists key events in the evolution of language policy in Canada since 1710, when the French-speaking population of Acadia first came under British administration. The timeline covers the policies of the colonial predecessors to the current Canadian state, and the policies of Canada's provinces and territories. The policies listed include: Legislative changes including constitutional amendments, acts of Parliament, and Orders in Council; Major policy announcements including abortive policy proposals that were never implemented; Key administrative initiatives governing the implementation of major policies; Court decisions relating to Canada's language laws.

These policy changes have been important to the extent that they affected the lives of individual Canadians. Therefore, in order to give some idea of the relative importance of various policies over the centuries, population statistics for Canada's different language groups are included where such information is available.

General themes in official languages policy Official languages policies, in one form or another, have been in existence since the beginning of the European colonization of North America. In the early years, French was the sole language used in New France while English had been the sole language of British America. The First Nations continued to use their indigenous languages in their own affairs. There were a limited number of people who knew both a European and a native North American language, often Christian missionaries the “black robes” and the children of natives they ministered to. These bilinguals were called on in diplomacy, but otherwise the linguistic worlds of the settlers and the natives were largely separate. Without being fluent, natives and settlers often learned very rudimentary forms of each other's languages called “pidgins”. Pidgins, such as the Algonquian–Basque pidgin, Labrador Inuit Pidgin French, American Indian Pidgin English, and Pidgin Delaware were initially important languages of trade and diplomacy, but none of them was ever prestigious enough to be used in any other governmental context.

The need for a considered language policy came with the absorption New France into the British Empire. This began with the Siege of Port Royal in 1710 followed by the conquest of New France in 1758. Britain was then ruling over a large population of non-English speaking white settlers. In what is now the eastern half of the country, some sort of accommodation was made for French during the long period of British colonial rule that followed, but at no point did the language achieve full legal and practical equality with English. The public reaction to this situation was one of the sources of the political instability that led to the adoption of a series of constitutions, culminating in the adoption of a federal structure in 1867 as a way of allowing the two languages to have different levels of official status in different provinces.

Following Confederation in 1867, French and English were treated as being fully equal within Quebec, in all matters under provincial jurisdiction. In matters under federal jurisdiction, English occupied a de facto privileged position, and French was not fully equal, although it did enjoy some constitutionally protected privileges. In other provinces, French was sometimes tolerated and sometimes actively suppressed. Other settler languages, such as Scottish Gaelic, Irish, and German were ignored in politics and increasingly suppressed with adoption of universal public education.

Aboriginal languages, which earlier Christian missionaries had studied and helped to document, came under sustained attack by a system of state-sponsored church-run residential schools beginning in the 1840s in the east and later extending across the country. These schools were part of a deliberate policy to suppress or eliminate indigenous languages in favour of English. Over the course of the Twentieth and early Twenty-first centuries, the two predominant settler languages, English and French, have gradually achieved a greater level of equality in most of Canada's provinces, and full equality at the federal level. The trend has been very different in Quebec, however, where in the 1970s English was formally deprived of its status of full legal equality. Today, French is, both de facto and de jure, the sole official language of Quebec.

Also since the 1970s and the adoption of the policy of multiculturalism in Canada, teaching of other languages besides English and French, not only as a separate subject but as the medium of instruction, has expanded dramatically, beginning primarily with European languages, notably Ukrainian, the policy changes at the provincial level have seen a boom in schools catering to a variety of language groups. For example, in Edmonton, Alberta in 2015 the Catholic school board offered full immersion in French, "bilingual programs" (one third to one half time immersion) in Polish, Spanish, and Ukrainian, and part-time language and culture programs in Filipino, Italian, Japanese, Korean, Spanish, and Nehiyaw Pimatisiwin (Cree). Likewise, the public school board offered American Sign Language Bilingual, Arabic Bilingual, Chinese (Mandarin) Bilingual, French Immersion, Late French Immersion, German Bilingual, Hebrew Bilingual, International Spanish Academy, Ukrainian International Bilingual, and Awasis (Cree) programs.

Official languages policy and legislation relating to the Province of Canada (1840-1867) and the Dominion of Canada (1867-present)

1840: The Act of Union is adopted. Section 41 of the Act bans the French language from Parliament and Courts of the new united Province of Canada. 1841: At the first meeting of the Legislative Assembly of the Province of Canada, Austin Cuvillier, a French-Canadian, is elected as the first Speaker. As well, the new Parliament adopts rules of order. Rule 29 provides for the translation of papers into French. Rule 38 provides for the reading of motions in both French and English.Standing Rules and Regulations of the Legislative Assembly of Canada (Kingston, 1841). 1841: The Parliament of the Province of Canada adopts An Act to provide for the translation into the French Language of the Laws of the Province, which ensures that a non-official copy of all Canadian laws will be "distributed among the People of this Province speaking the French language, in the same manner in which the English text of the said Laws shall be printed and distributed among those speaking the English language...." 1848: Article 41 of the Act of Union is amended. In a return to the situation that had existed from 1792 to 1837 in Lower Canada, it is once again legal to use the French language in the Parliament and in the Courts. 1857: Section 15 of the Act respecting the Codification of the Laws of Lower Canada relative to Civil Matters and Procedure requires that the Civil Code of Lower Canada be printed only in bilingual form, with English and French displayed on the same page: “[T]he two texts, when printed, shall stand side by side.” Side-by-side publication is a first step towards the adoption of the "Equal Authenticity Rule" for interpreting bilingual statutes.It has even been suggested that this section is "best understood as a non-verbal legislative sign that the two texts should be interpreted dialogically." Source: Michel Bastarache, Naiomi Metallic, Regan Morris and Christopher Essert, The Law of Bilingual Interpretation. Toronto: LexisNexis, 2008, p. vi. 1867: Section 133 of the British North America Act, 1867 (later renamed the Constitution Act, 1867) decrees that "The Acts of the Parliament of Canada and of the Legislature of Quebec shall be printed and published in both those Languages [ie. in both English and French]", and also mandates the use of both French and English for parliamentary debates, parliamentary publications, and federal court cases. 1935: R. v. DuBois: The Supreme Court of Canada applies the rule of judicial interpretation that will come to be known as the “Equal Authenticity Rule” to Acts of Parliament. This rule of interpretation holds that section 133 of the Constitution Act, 1867 requires courts to treat “both [the English and French] versions of statutes [as] equally valid and authoritative interpretations of the law,”This definition of the equal authenticity rule is from Michel Bastarache, Naiomi Metallic, Regan Morris and Christopher Essert, The Law of Bilingual Interpretation. Markham, Ontario: LexisNexis, 2008, p. 17. even if the statute in question was clearly drafted in one language and translated into the other, and even if the two versions of the law are incompatible. This rule had been applied to Quebec legislation since 1891, as a consequence of the court's ruling in CPR v. Robinson. 1959: The Conservative government of John Diefenbaker introduces simultaneous interpretation in the House of Commons. Prior to this, the right to use English or French in Parliament had been guaranteed, but unilingual MPs had been unable to understand each other's speeches. 1962: From this date, family allowance cheques are mailed in bilingual form, nationwide. 1963: The Liberal government of Lester Pearson establishes the Royal Commission on Bilingualism and Biculturalism “to inquire into and report upon the existing state of bilingualism and biculturalism in Canada.”. 1963: The Pearson government established an interdepartmental committee of senior public servants to report regarding measures to promote bilingualism in the Public Service. 1964: The first language school for Public Servants opens. 1964: A private member's bill, initiated by Liberal backbencher Jean Chrétien, gives Canada's state-owned airline, Trans-Canada Air Lines, the new bilingual name "Air Canada," starting a trend of giving bilingual names to federal institutions which formerly had borne English-only names. 1968: From this date forward, statutes of Canada are printed with the English and French texts of the law side by side, rather than in separate volumes. This "allows for a first-hand comparison of both texts...."The full quotation is: The province of Quebec even prints both texts in the same volume opposite each other on the page. This, of course, allows for a first-hand comparison of both texts, something not possible at present with federal statutes." Ironically, these words, which were written before 1968, were not published until 1971, after the problem to which they referred had been corrected. See Claude-Armand Sheppard, The Law of Languages in Canada, p. 68. Side-by-side publication is an indication of the internalization, within the Canadian parliament, of the "Equal Authenticity Rule". 1965: The Royal Commission on Bilingualism and Biculturalism releases a Preliminary Report that underlined the cultural and linguistic duality of Canadian society.