After commissioning on 12 December 1941, she made a short trip to Iceland with the battleship King George V, then escorted a British convoy to India.

In early April 1942, Panther rescued survivors from two cruisers sunk in the Indian Ocean, after which she took part in Operation Ironclad, the Allied invasion of Vichy French-held Madagascar, and sank a French submarine with another destroyer.

Panther then returned to the Mediterranean, and participated in the Allied landings in North Africa, but was severely damaged in an air attack and had to undergo repairs in Gibraltar.

The ships carried a maximum of 500 long tons (510 t) of fuel oil that gave them a range of 3,850 nautical miles (7,130 km; 4,430 mi) at 20 knots (37 km/h; 23 mph).

[3] After sea trials and working up in the River Clyde area, Panther departed for Scapa Flow and arrived there on 1 January 1942.

On 5 April however, two of the British cruisers, HMS Cornwall and Dorsetshire, were sunk by Japanese aircraft; Panther was ordered to collect survivors.

On 8 May, in conjunction with the destroyer Active she sank the Vichy French submarine Monge, which was attempting to attack British ships.

In November, she escorted ships during the Allied landings in North Africa, and was severely damaged in an air attack; three men were killed and ten more injured.

[3] During the next three months, Panther, now with the 14th Destroyer Flotilla, took part in Operation Husky, the Allied invasion of Sicily; she screened major ships from submarine attacks and bombarded Italian targets.

On 9 October, Panther was sailing south of the Scarpento Channel with other Allied vessels; the naval force came under air attack by Junkers Ju 87 Stuka aircraft of I.