Argonaut's first mission was to bring some reinforcements, several 3.7" guns and some Norwegian soldiers, to Spitzbergen island. She set sail on October 13th 1942. From there she continued to Murmansk as part of a convoy escort.

Back home, Argonaut left Scapa Flow on October 30th as part of a fleet bound for North Africa as part of Force H, comprising battleships HMS Nelson, HMS Duke of York, HMS Renown, joined later by carriers HMS Illustrious and HMS Formidable. They were going to take part in Operation Torch, the invasion of the French North Africa. During that operation, Argonaut was dispatched as a decoy ship, sending false signals to confuse the Axis forces.

In December 1942, Argonaut joined Force Q. Along with cruisers HMS Aurora and HMS Sirius and destroyers HMS Quentin and HMAS Quiberon. On December 1st the force found an Axis convoy, and engaged in an hour battle, in which the Italian destroyer Folgore and four troopships were sunk, and destroyer Da Recco and a torpedo-boat were damaged. On their way back, they suffered an air attack in which Quentin was sunk. On December 13th Argonaut joined cruiser Aurora and destroyers HMS Eskimo and HMS Quality, and they left Bone to intercept another Axis convoy, which they missed. Instead, on December 14th Argonaut was torpedoed by Italian submarine Mocenigo in position 37.30N, 08.13E. Two torpedoes struck the ship, and blew off both stern and bow. Amazingly, only three crewmen lost their lives in the explosions. Argonaut managed to get to Gibraltar. Provisional repairs proved to be precaroius, and on April 4th 1943 she set sail to Philadelphia, escorted by the destroyer HMS Hero. After a brief scale in the Azores, Hero had engine problems and had to leave Argonaut on her own on April 9th. On April 13th she was sighted by the American destroyer USS Butler, that escorted her to Bermuda, where some additional repairs were done. Escorted by the American minesweepers USS Tumult and USS Pioneer, she reached Philadelphia on April 27th.

The repairs were completed on November 13th 1943. In December 1943, Argonaut joined the Home Fleet and was attached to the 10th Cruiser Division. She took part in the invasion of Normandy, where she fired 4359 shells. Again a lucky ship, she was hit by a German artillery shell that penetrated the quarterdeck and emerged by the starboard side without exploding and without a single casualty.

In August 1944 Argonaut was transferred to the Mediterranean Fleet, where she took part in Operation Dragoon (the invasion of Southern France) In September 1944 she was moved to the Aegean Sea, and saw action when she spotted some boats carrying troops, which she sunk, taking many prisoners. She was also involved in some shore bombardments in the Greek coast.

In early November she was ordered to Trincomalee, in the Indian Ocean. She was assigned in escort duties, and involved in the bombardment of Palembang oil fields in Sumatra. She was lucky once more: attacked several times by kamikaze aircrafts, she sustained only minor damages. In January 1945 Argonaut was ordered to Sydney, to join the Pacific Fleet. In February she took part in the shelling of Saskishima (the diversion operation from the main American operation in Okinawa). In August 1945 she sailed to Formosa, to help with the evacuation of British prisoners of war. The same mission brought her to Hong Kong later.

She finally returned to Portsmouth on 6 July 1946, where she was sent to reserve, neved to be recommissioned again. Her last trip was to the Cashmore scrapyard at Newport, South Wales, UK for disposal where she arrived on 19 November 1955.