HMAS Australia was ordered as part of a five year naval development programme. Originally completed with short funnels, which were later raised by 15 feet. This class of vessel was designed by Sir Eustace Tennyson d`Eyncourt. Although on paper, this class appeared to be inferior to contemporary cruisers of other navies. They were superior in sea going qualities and had accommodation and liability which was not equalised elsewhere. In addition a considerable amount of weight had been expended in structural strength, and internal protection. No attempt had been made to attain the high speeds, but the ideal being aimed at being the ability to sustain the designed speed indefinitely and in all weathers, without exceeding the normal horse power, actually over 34 kts has been maintained in service without in any way pressing the boilers.

On 23 October 1928 October, she arrived in Sydney and spent the next six years in Australian waters. In December 1934, she sailed for UK on exchange with Sussex. In April 1936, she returned to Sydney and was employed in Australian and Pacific waters. In August she paid off into reserve, and a major refit was carried out. 4 twin 4” AA mounts replaced the original singles.

In September 1939 her refit and modernisation was completed at Melbourne. In January 1940 she was in the Indian Ocean, on convoy escort duties for troop transports leaving from Sydney. In May she was escorting troop convoys from Wellington (New Zealand) to Sydney, Australia. In June the Australian naval board informed the Admiralty that the Commonwealth Government proposed that the cruiser should be placed at the Admiralty’s disposition immediately for service in Home or Mediterranean waters. That same month Italy declared war, HMAS Australia was in Simonstown, South Africa. For the remainder of that month she was involved in escort duties from Cape Town to Durban. In July, she was ordered by the C. in C. South Atlantic, Vice Admiral D'Oyly Lyon to sail and rendezvous with the cruiser HMS Dorsetshire and the aircraft carrier HMS Hermes off Dakar, an hour later she left from Freetown. Their task was to observe the French naval forces off Dakar. On the 12th, the British Government decided to take no further action against the French vessels in French colonial or North African ports. On the 20th, HMAS Australia joined the 1st cruiser squadron based at Scapa Flow. In August, in company with the cruiser HMS Norfolk she left Scapa Flow for Bear Island area tasked to intercept German fishing boats, however the mission was aborted due to bad weather.

In September 1940, HMAS Australia was called upon to relieve the cruiser HMS Fiji after that ship had been damaged by torpedo from U-32 whilst escorting a Dakar bound convoy, she narrowly missed being torpedoed herself on the 8th, by U-56, but because of a malfunctioning torpedo, she escaped. On the 18th, three French cruisers left Dakar and HMAS Australia and the cruiser HMS Cumberland were ordered to shadow them. The French operation against Gabon was thus prevented and two of the French cruisers returned to Dakar (one had developed engine trouble earlier and was escorted to Casablanca). On the 23-24th of the same month British naval forces attacked Dakar for the purpose of preparing a landing force of Free French troops. HMAS Australia inflicted heavy shell hits on the large French destroyer L’Audacieux setting her on fire, her crew beached the vessel. The next day the cruiser shelled coastal batteries and the ships lying in the Harbour. She herself was under accurate fire from the French cruisers and whilst reversing course at the end of a run, she was twice hit aft, the 6"shells caused no casualties. At 0912 the cruiser Devonshire signalled "cruisers withdraw" it was during the withdrawal that HMAS Australia suffered her casualties. From the bridge an aircraft astern was seen to be shot down, but not until later was it learned that it was the cruiser`s Walrus which was lost together with its crew. On the 28th, the cruiser was instructed to return to the U.K.

In October, she once again joined the Home Fleet, and was based at Greenock occupied mostly on patrol and escort work. On 18 November 1940, she docked at Liverpool for a refit, slight damage was suffered by her in the dock when a 500lb bomb fell near the port quarter damaging the aircraft catapult.

In January 1941, HMAS Australia left Liverpool, as ocean escort to a convoy destined for the Middle East via the Cape, she entered the Indian Ocean on February, and on the 22nd of that month, turned the convoy (then off Mombassa and bound north for the Gulf of Aden) over to the cruiser HMS Hawkins, whilst she herself joined in the hunt for the German pocket battleship Admiral Scheer, which was reported to be in the area. After this fruitless search, she escorted the troop ships Mauretania and Nieuw Amsterdam from Colombo towards Australia to form part of convoy US-10, and arrived in Sydney on 24 March. April 1941 was spent escorting a convoy, and at the end of the month, she carried Admiral Colvin and his staff from Singapore to Sydney after the Singapore conference. June saw the cruiser escorting convoys in the Tasman Sea and for the remainder of 1941 she was on escort and patrol duties on the South Atlantic station, this period however, included a brief visit to Kerguelen Island, to seek a possible German raider.

In December 1941 HMAS Australia was escorting a convoy between St. Helena and Capetown when on the 3rd, she was ordered by the Admiralty to hand over responsibility to HMS Dorsetshire and proceed at once towards Fremantle. This was consequent upon the loss of the Australian cruiser HMAS Sydney and the threatening situation in the Far East. On the 24th, in Sydney Rear Admiral Crace transferred his flag from HMAS Canberra to HMAS Australia. On the 28th, convoy ZK-5 with 3 large transports, 4,250 troops and 10,000 tons of supplies, set out from Brisbane for Port Moresby, escorted by HMAS Australia and the cruisers HMAS Canberra, HMAS Perth and HMNZS Achilles.

In February HMAS Australia was operating with the ANZAC forces near the New Hebrides under the command of Rear Admiral Crace, RN. March saw her operating with the American navy as a covering group south east of Papua. In April 1942 the ANZAC Squadron became Task Force 44. During May HMAS australia was a member of the support forces for the American aircraft carriers involved in the air battle in the Coral Sea. In June she was still serving in the Pacific as a member of Task Force 44 in company with HMAS Canberra and HMAS Hobart, operating in Australian and New Zealand waters. Rear Admiral Crutchley, RN was in command. During July / August, Australia was employed as a member of the covering force for a troop transport convoy organised for the US landings on Guadalcanal, and at the end of August, Australia was deployed as a covering force for US carrier groups east of the Solomon Islands.

In February 1943, HMAS Australia assisted the covering force south of Australia for the convoy code named "Pamphlet”, consisting of transport vessels conveying 3,000 men of the 9th Australian Division which was proceeding from Suez to Sydney and Melbourne. By March she was a member of Task Force 74 ,a part of the US 7th Fleet, commanded by Admiral Carpender. In June she was deployed in the Eastern Arafura Sea to cover the US landings on New Georgia (central Solomons) and in July she in company with HMAS Hobart were deployed from Espiritu Santo to the north west to make good the losses in the fighting off New Georgia, it was here that on 20 July the Hobart was torpedoed by the Japanese submarine I-11 (offsite link), and put out of action for nearly two years. In November, the Australian cruiser HMAS Shropshire joined HMAS Australia and was temporarily transferred from Milme Bay to the New Hebrides to reinforce the South Pacific forces. In December, Australia supported the landing of 1600 men of the 112th US Cavalry on Arawe (New Britain) later that month the US 7th amphibious force landed 13,000 troops of the US 1st marine division at Cape Gloucester, with fire support coming from Australia and Shropshire. HMAS Shropshire

1944 January, 2,400 troops of the 32nd US infantry division were landed near Saidor (New Guinea) HMAS Australia and HMAS Shropshire made up the covering force. In April they were the covering force for the US landings on Holandia and Aitape. During July they were deployed in shelling Japanese troops who were trying to break through to the west in the area of Aitape. In September they were employed in the shelling of Morotai prior to the US landings there and the covering of the forces October, covering force for the air attack on airfields on Mindanao. On 20 November 1944, a Japanese Kamakaze aircraft crashed into Australia causing heavy damage and casualties and forcing her withdrawal from further action.

In January 1945, HMAS Australia gave fire support provided for the US landings in the Lingayen Gulf area, but on the 5th, Australia was seriously damaged by hits from five Kamikaze aircraft in this action, however she continued to carry out her bombardment duties until ordered to retire on the 9th. After this date she saw no more action.

After the war she served as the RAN flagship for several years. Following repairs to the Kamikaze damage, partly carried out in Australia, and completed in the U.K., she had X turret removed and had a modern R.N. pattern director control tower on the bridge. She was fitted with type 285 radar, a high angle direction control tower with type 285 radar was fitted on the centre line, forward of the mainmast. She was unusual in that her 4"guns were mounted one deck lower. After recommissioning once more she became the Fleet Flagship. In 1950 Australia was deployed as a training ship. On 31 August 1954, the cruiser was finally paid off. On 25 January 1955 she was sold for scrap. On 26 March 1955 Australia left Sydney in tow, bound for the U.K. where she was broken up for scrap by Ward at Barrow-in Furness.