His Majesty's Canadian Ship

The designation Her Majesty's Canadian Ship (HMCS) (in French Navire canadien de Sa Majesté [NCSM]), is applied as a prefix to surface ships in the Royal Canadian Navy and Canadian Joint Operations Command. The similar designation of Her Majesty's Canadian Submarine is applied to submarine vessels.

In the reign of a king, the designation changes to His Majesty's Canadian Ship; the French version of the title remains unchanged in this instance. The title is derived from Her Majesty's Ship (HMS), used in the United Kingdom. The person who is monarch of Canada is also equally and separately the monarch of the United Kingdom of Great Britain and Northern Ireland.

Various Commonwealth realms use derivative variations to designate their warships, such as Her Majesty's Australian Ship (HMAS) and Her Majesty's New Zealand Ship (HMNZS).

After the formation of Naval Service of Canada in 1910, warships were given the prefix HMCS with the "C" representing Canadian as a way to differentiate Canadian from British warships. It was initially the only concession the British Admiralty made following the formation of the Canadian naval service.HMCS Rainbow was the first ship with the HMCS designation after being transferred from the British Royal Navy to Canada, commissioned on 4 August 1910.HMCS Haida became the first Canadian ship commissioned under a Queen during March 1952.

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