Events from the year 1865 in Canada.
- February 3 - Legislature approves message to Crown for union of British North America provinces.
- February 20 - The Legislature of the Province of Canada passes a motion in favour of Confederation
- March 7 - New Brunswick rejects a Confederation scheme.
- March 24 - Macdonald, Brown, Cartier, Galt appointed to negotiate Confederation in London.
- May 10 - An admiralty letter to the Colonial Office required colonial warships to "wear a Union Jack in the usual place, and the White Ensign, with either the Arms of the Colony, or such other distinguishing mark as may be chosen by the Colony, and approved by the Colonial Office and the Lords Commissioners of the Admiralty". This regulation was mainly directed at Australia and not applicable to Canada, which had no Navy at that time.
- October 20 - Proclamation of Ottawa as seat of government.
- November 7 - Newfoundland general election, 1865
- December 16 - A distinctive Blue Ensign for the province of Canada is authorized by the UK secretary of state for the colonies.
- December 22 - Colonial Office Circular notifying revised Admiralty requirements for flags for colonial warships and for other colonial government vessels and requesting correct drawings of seals or badges to be adopted as distinguishing marks.
Full date unknown
- January 16 - Joseph Cunard, merchant, shipbuilder and politician (born 1799)
- July 27 - Augustin-Norbert Morin, lawyer, judge, politician and Joint Premier of the Province of Canada (born 1803)
- July 30 - Étienne-Paschal Taché, doctor, politician, and deputy adjutant-general of the militia (born 1795)
- August 27 - Thomas Chandler Haliburton, author, judge and politician (born 1796)