[2] After a successful 'Warship Week' National Savings campaign in March 1942 the ship was adopted by the civil community of Widnes, Lancashire Black Swan was initially deployed on convoy escort missions along the British east coast, before the Norwegian Campaign caused Black Swan to be attached to the Home Fleet, where it was used to provide anti-aircraft cover to the Allied landings at Åndalsnes.

On 2 April 1943, when escorting Convoy OS 45, from Liverpool to Freetown, Black Swan and the Flower-class corvette HMS Stonecrop sank the top-scoring U-boat U-124 with all hands off the coast of Portugal.

[8] In 1943 Black Swan for a short time saw action near Iceland to provide escort against the U-boat threat, after which she served in the Mediterranean, on Malta and Adriatic convoy protection duties.

At the end of hostilities in 1945 Black Swan followed the cruiser HMS Belfast into Shanghai and were the first Royal Navy warships to liberate Japanese concentration camps containing British and Empire prisoners.

Black Swan suffered 12 men wounded and severe damage to her superstructure in a fierce engagement with Chinese batteries and fell back.