HMCS Rosthern was a Flower-class corvette that served in the Royal Canadian Navy during the Second World War.

[3][4][5] The "corvette" designation was created by the French for classes of small warships; the Royal Navy borrowed the term for a period but discontinued its use in 1877.

[11] After arriving at Halifax for deployment, Rosthern initially joined Newfoundland Command, escorting convoys between St. John's and Iceland.

[11] During these convoy battles, Rosthern picked up survivors from several merchants ships including on 29 October 1942 when she and HMCS Summerside together picked up survivors from the American tanker Pan New York that was damaged by U-624 in the North Atlantic about 550 nautical miles (1,020 km) west of Malin Head.

During the battle for Convoy SC 121, Rosthern picked up three survivors from the British merchant Egyptian, which had been sunk.

[10] In late May 1944, Rosthern returned to Canada to become a training ship for navigation and handling at Halifax.

She remained with this unit until the end of the war, her final significant duty was escorting HMCS Provider back to Canada.