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).
HMCS Rainbow was the first ship with the HMCS designation. It transferred from the British Royal Navy to the Naval Service of Canada in 1910. HMCS Haida became the first Canadian ship commissioned under a Queen during March 1952.
Many RCN shore facilities also bear the designation, such as HMCS Trinity, HMCS Chippawa, HMCS Naden, HMCS Discovery, HMCS Stone Frigate, and all Royal Canadian Sea Cadets summer training centres, such as HMCS Quadra.
Shore maintenance and mooring facilities bear the name Her Majesty's Canadian Dockyard (HMC Dockyard) (in French L’arsenal canadien de Sa Majesté (Arsenal CSM)).