HMCS Cobalt was a Flower-class corvette of the Royal Canadian Navy which took part in convoy escort duties during the Second World War.

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

On 22 January 1941 she took part in the Canadian Navy's first secret trial of diffused lighting camouflage, a technology for concealing ships from submarines at night.

[13] Following completion of her first refit, Cobalt made two round trips to Derry before being assigned in May 1942 to the Western Local Escort Force (WLEF), with which she was to spend the balance of the war.

[13] Cobalt was paid off at Sorel, Quebec on 17 June 1945 and subsequently sold for conversion to a whale-catcher, entering service in 1953 as the Dutch Johanna W. Vinke.