The National Flag of Canada, also called the Maple Leaf, was adopted in 1965. There have been many flags used for various purposes by Canadian government officials and the military, each with a different meaning.

Since the 1700s, the maple leaf has stood for the people and land of Canada. It is fitting, since maple trees are found throughout the country. It had appeared on decorations in 1816 when the Prince of Wales visited, and on the coats-of-arms of the provinces of Ontario and Quebec.
There is no significance attached to the number of points. The maple design was chosen after wind tunnel tests showed it to be easier to see in high wind conditions. In other words, it was less blurry in high winds. The maple leaf also represents industries in Canada. These include the production of maple syrup, and the building of furniture and cabinets.
On February 15, 1965 the Speaker of the Senate, the Honorable Maurice Bourget, was quoted about the flag:
"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."
Red and white were proclaimed the official colors of Canada in 1921 by King George V. According to the Department of Canadian Heritage, the red was taken from St. George’s Cross, an early emblem of England, the white from the French Royal Emblem. This incorporated both the French and English involvement in Canadian history.
The first flag was the fleur-de-lis, the flag of medieval France. It has three gold fleurs-de-lis on a blue background. It was used from 1534, when Jacques Cartier claimed the land for France, until the early 1760s. At that time, Canada became part of the United Kingdom.
The Royal Union flag, also referred to as the Union Jack, was then the official British flag. This flag was redesigned after 1800, when the United Kingdom of Great Britain included England, Ireland, and Scotland. It used England’s St. George’s Cross, Scotland’s Cross of St. Andrew, and Ireland’s Cross of St. Patrick and melded them in the British flag you see today.
In 1707, the British Merchant Marine created a flag named the Red Ensign. It had the Union Jack in the upper left corner. A symbol was added incorporating the symbols of New Brunswick, Nova Scotia, Ontario, and Quebec and the flag was used on both land and sea from 1870 to 1904. It was made official in 1892 and renamed the Canadian Red Ensign.
Whenever a new province entered the Confederation, its emblem was added to the shield. In 1922, the shield was replaced with the Canadian Coat of Arms, and two years later, it was officially approved for use on government buildings in other countries. By 1945, it was used on government buildings within Canada and continued to be flown until the adoption of the current Canadian flag.
Canadians started looking for a new flag in 1925. A committee was formed, but its work was never completed. In 1964, the search was resumed and a new committee asked for submissions. Some designs incorporated the fleur-de-lis and the Union Jack (the British flag), one had three maple leaves, and another had three red maple leaves between two blue borders. Dr George Stanley, from the Royal Military College, pointed out to the committee that the flag at the college, with a single fist in a red and white background, was bold. He and Mr. John Matheson came up with the winning design.
The national colors of Canada, red and white were used, along with a single, maple leaf. The red maple leaf is on a white background, and is bordered by red. An interesting fact is that Canadian Olympics have worn an emblem with a red maple leaf on a white background since 1904.