HMAS Canberra (I33/D33), named after the Australian capital city of Canberra, was a Royal Australian Navy (RAN) heavy cruiser of the Kent sub-class of County-class cruisers. Constructed in Scotland during the mid-1920s, the ship was commissioned in 1928, and spent the first part of her career operating primarily in Australian waters, with some deployments to the China Station.

At the start of World War II, Canberra was initially used for patrols and convoy escort around Australia. In July 1940, she was reassigned as a convoy escort between Western Australia, Sri Lanka, and South Africa. During this deployment, which ended in mid-1941, Canberra was involved in the hunt for several German auxiliary cruisers. The cruiser resumed operations in Australian waters, but when Japan entered the war, she was quickly reassigned to convoy duties around New Guinea, interspersed with operations in Malaysian and Javanese waters. Canberra later joined Task Force 44, and was involved in the Guadalcanal campaign and the Tulagi landings.

On 9 August 1942, Canberra was struck by the opening Japanese shots of the Battle of Savo Island, and was quickly crippled, and according to the crew, she was torpedoed by friendly fire. Unable to propel herself, listing heavily and burning, the cruiser was evacuated and then sunk in Ironbottom Sound by two American destroyers. The United States Navy Baltimore-class cruiser USS Canberra was named in honour of the Australian ship. Later, in 2023, the US Navy named the new Independence-class littoral combat ship USS Canberra after Canberra, which became the first US warship commissioned in a foreign port.

Canberra was one of seven Kent-class cruisers—a subclass of the County-class cruiser—designed by Eustace Tennyson-d'Eyncourt. The ship was 590 feet (180 m) long between perpendiculars and 630 feet 1 inch (192.05 m) overall, with a beam of 68.25 feet (20.80 m), and a maximum draught of 21 feet 4 inches (6.50 m). She displaced 9,850 tons at light load, and 10,000 tons at standard load. The Kent class were built to meet the restrictions of the Washington Naval Treaty; with a reduction in armament and protection. Canberra was powered by eight Yarrow boilers which fed steam to four Brown-Curtis geared turbines; these in turn provided 80,000 shaft horsepower (60,000 kW) to the ship's four propeller shafts. The cruiser could reach speeds of 31.5 knots (58.3 km/h; 36.2 mph), which could be maintained for 2,870 nautical miles (5,320 km), although 13,200 nautical miles (24,400 km) could be travelled at the more economical 12-knot (22 km/h; 14 mph) standard cruising speed. Before World War II, the ship's company was normally 690 (49 officers, 641 sailors); this increased to 710 when acting as a flagship. During wartime service, the normal company expanded to 751 (61 officers, 690 sailors), and at the time of her loss, 819 people were aboard.

Canberra's main armament consisted of eight 8-inch Mark VIII guns in four twin turrets. Secondary armament consisted of four 4-inch quick-firing high-angle guns and four 2-pounder "pom-pom" guns. A mixture of .303-inch machine guns were carried for close defence work: initially this consisted of four Vickers machine guns and twelve Lewis machine guns, although four Lewis guns were later removed. During a refit in 1942, two multiple pom-poms and five 20 mm Oerlikons were added to enhance the anti-aircraft armament. Four 3-pounder quick-firing Hotchkiss guns were used as saluting guns. Two sets of quadruple 21-inch torpedo tubes were fitted. Depth charges were carried: these were deployed by rails.

The cruiser was designed to carry a single amphibious aircraft: initially a Supermarine Seagull III aircraft, but this was replaced in 1936 by the Supermarine Walrus. However, the aircraft catapult was not installed until April 1936, during a refit in Sydney. Before this, the Seagull amphibian was lowered into the water by the ship's recovery crane and took off from there. Armour aboard Canberra was limited to an armour deck over the machinery spaces and magazines, ranging from 1.5 to 3 inches (38 to 76 mm) in thickness. Armour plate was also fitted to the turrets (up to 2 inches (51 mm) thick) and the conning tower (3 inches (76 mm) thick). Anti-torpedo bulges were also fitted.

In 1924, the Australian government ordered two Kent-class cruisers to replace the ageing light cruisers Sydney and Melbourne. These ships were to be named Australia and Canberra, with both to be built by John Brown & Company, at their shipyard at Clydebank, Scotland: the only two County-class ships built in Scotland. Canberra was laid down on 9 September 1925, and given the yard number 513. Canberra was launched on 31 May 1927 by Princess Mary; the first ship of the RAN launched by a member of the Royal Family. Work on the ship was completed on 10 July 1928, the day after the cruiser was commissioned into the RAN. Most of the initial ship's company came from Sydney. Canberra cost approximately A£2 million to construct.

Canberra left Portsmouth on 4 December 1928, after several months of workup trials, and arrived at Sydney on 16 February 1929. The cruiser operated primarily in Australian waters during the next ten years, spending periods of time as the RAN flagship. On 20 September 1929, during a round-Australia cruise, the ship grounded on a sand shoal outside Roebuck Bay, Western Australia. The damage did not prevent the ship from operating, and it was not until early 1930 that the affected hull plates were replaced. In September 1931, Canberra visited New Caledonia and Fiji. The cruiser operated on the Royal Navy's China Station in 1932 and 1937. In 1934 the ship was assigned to escort HMS Sussex, which was transporting the Duke of Gloucester during a visit to Australia. In August 1936 she brought Admiral Sir Murray Anderson to Sydney, Australia to be invested as Governor of New South Wales.