31 Dec, 1941
The German submarine U-87 torpedoed and damages the British merchant Cardita about 110 miles bearing 307 from St.Kilda in position 59º18'N, 12º50'W. The vessel foundered in 3 January 1942 in position in 59º42'N, 11º58'W.

HMS Onslow (Capt H.T. Armstrong, DSC, RN) later picks up 23 of the crew.

14 Sep, 1942
The German submarine U-589 was sunk in the Arctic Ocean south-west of Spitzbergen, in position 75º40'N, 20º32'E, by depth charges from the British destroyer HMS Onslow, and depth charges from a Swordfish aircraft of the escort carrier HMS Avenger (Sqdn 825). (see map)

31 Dec, 1942
As part of the escort of convoy JW51B bound to Murmank, she was involved in the action when the convoy was attacked by the German heavy cruiser Hipper in the Barents Sea. Onslow was badly damaged, with a high toll in dead and wounded. Among the wounded was her CO, Captain Sherbrooke, who lost an eye in the battle and suffered other injuries, and was awarded the Victoria Cross for the successful defence of the convoy, that suffered no losses of merchant ships.

12 Jan, 1945
The British heavy cruiser HMS Norfolk (Capt. J.G.Y. Loveband, RN with Rear-Admiral R.R. McGrigor, CB, DSO, RN aboard) and the light cruiser HMS Bellona (Capt. C.F.W. Norris, DSO, RN) escorted by the destroyers HMS Onslow (Capt. H.W.S. Browning, OBE, RN), HMS Orwell (Lt.Cdr. J.R. Gower, DSC, RN) and HMS Onslaught (Cdr. the Hon. A. Pleydell-Bouverie, RN) attack a German convoy of Egersund, Norway. Two German merchants, the Bahia Camarones (8551 GRT) and the Charlotte (4404 GRT) and the minelayer M 273 were sunk.