Out of three choices, the maple leaf design by Mount Allison University historian George Stanley,[4] based on the flag of the Royal Military College of Canada, was selected.

In heraldic terminology, the flag's blazon as outlined on the original royal proclamation is "gules on a Canadian pale argent a maple leaf of the first".

[14] In 1867, Alexander Muir composed the patriotic song "The Maple Leaf Forever", which became an unofficial anthem in English-speaking Canada.

[21] The Department of Canadian Heritage has listed the various colour shades for printing ink that should be used when reproducing the Canadian flag; these include:[9] The number of points on the leaf has no special significance;[22] the number and arrangement of the points were chosen after wind tunnel tests showed the current design to be the least blurry of the various designs when tested under high-wind conditions.

[6][36] The United Empire Loyalist flag, that is very similar to the Union Jack, was used by immigrants who remained loyal to the British crown during the American Revolutionary War.

[39] The composite shield was replaced with the coat of arms of Canada upon its grant in 1921, and in 1924, an Order in Council approved its use for Canadian government buildings abroad.

[6] In 1925, Prime Minister William Lyon Mackenzie King established a committee to design a flag to be used at home, but it was dissolved before the final report could be delivered.

A joint committee of the Senate and House of Commons was appointed on November 8, 1945, to recommend a national flag to officially adopt.

[39] By May 9 the following year, the committee reported back with a recommendation "that the national flag of Canada should be the Canadian red ensign with a maple leaf in autumn golden colours in a bordered background of white".

[46] In 1963, the minority Liberal government of Lester B. Pearson gained power and decided to adopt an official Canadian flag through parliamentary debate.

The main opponent to changing the flag was the leader of the opposition and former prime minister, John Diefenbaker, who eventually made the subject a personal crusade.

[48] In 1961, Leader of the Opposition Lester Pearson asked John Ross Matheson to begin researching what it would take for Canada to have a new flag.

This motion led to weeks of acrimonious debate in the House of Commons and the design came to be known as the "Pearson Pennant",[50] derided by the media and viewed as a "concession to Québec".

[39] A new all-party committee was formed in September 1964, comprising seven Liberals, five Conservatives, one New Democrat, one Social Crediter, and one Créditiste, with Herman Batten as chairman, while John Matheson acted as Pearson's right-hand man.

[39] Among those who gave their opinions to the group was Duguid, expressing the same views as he had in 1945, insisting on a design using three maple leaves; Arthur R. M. Lower, stressing the need for a distinctly Canadian emblem; Marcel Trudel, arguing for symbols of Canada's founding nations, which did not include the maple leaf (a thought shared by Diefenbaker); and A. Y. Jackson, providing his own suggested designs.

Stanley and Matheson collaborated on a design that was, after six months of debate and 308 speeches,[39] passed by a majority vote in the House of Commons on December 15, 1964.

[55] This parchment was signed discreetly by the calligrapher but was made official by the signatures of Queen Elizabeth II (given on January 28, 1965[20]), Prime Minister Lester Pearson, and Attorney General Guy Favreau.

This transport to different climates, combined with the quality of the materials with which the proclamation was created and the subsequent storage and repair methods (including the use of Scotch Tape), contributed to the deterioration of the document: The gouache was flaking off, leaving gaps in the heraldic designs, most conspicuously on the red maple leaf of the flag design in the centre of the sheet, and the adhesive from the tape had left stains.

A desire to have the proclamation as part of a display at the Canadian Museum of Civilization marking the flag's 25th anniversary led to its restoration in 1989.

[55] The new national flag was inaugurated on February 15, 1965, at an official ceremony held on Parliament Hill in Ottawa, in the presence of Governor General Major-General Georges Vanier, the Prime Minister, other members of the Cabinet, and Canadian parliamentarians.

[57] Maurice Bourget, Speaker of the Senate, said: "The flag is the symbol of the nation's unity, for it, beyond any doubt, represents all the citizens of Canada without distinction of race, language, belief, or opinion.

[58] At the time of the 50th anniversary of the flag in 2015, the government—held by the Conservative Party—was criticized for the lack of an official ceremony dedicated to the date; accusations of partisanship were levelled.

[57] Minister of Canadian Heritage Shelly Glover denied the charges, and others, including Liberal Members of Parliament, pointed to community events taking place around the country.

[57] Governor General David Johnston did, though, preside at an official ceremony at Confederation Park in Ottawa, integrated with Winterlude.

"[59] Queen Elizabeth II stated: "On this, the 50th anniversary of the National Flag of Canada, I am pleased to join with all Canadians in the celebration of this unique and cherished symbol of our country and identity.

[61] The Royal Standard of Canada (banner of arms) is an official flag introduced May 6, 2023, and first flown at Government House, Halifax, that day.

The suggestions, titled National Flag of Canada Etiquette, were published by Canadian Heritage online and last updated in 24 February 2022.