1865 in Canada

10 May: 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.

16 December: A distinctive Blue Ensign for the province of Canada is authorized by the U.K. secretary of state for the colonies.

22 December: 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.