HMCS Trillium 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.

[8] Trillium was ordered 20 January 1940 for the Royal Navy as part of the 1939-1940 Flower-class building program.

She could be told apart from other Canadian Flowers by her lack of minesweeping gear and the siting of the after gun tub amidships.

The first took place at Lunenburg, Nova Scotia beginning in August 1941 and taking three months to complete.

Her third refit saw her fo'c'sle extended at Boston beginning in April 1943 and was completed 10 June 1943.

[9] The final refit of her career took place in late April 1944 at Pictou, Nova Scotia and lasted two months.

[10] On 21 April 1941 she picked up 24 survivors from the British merchant Empire Endurance that had been torpedoed and sunk the previous southwest of Rockall.

After workups in Bermuda and returning to service, Trillium was assigned to MOEF group C-3 in September 1944.