HMS Canopus was a pre-dreadnoughtbattleship of the British Royal Navy and the lead ship of the Canopus class. Intended for service in Asia, Canopus and her sister ships were smaller and faster than the preceding Majestic-class battleships, but retained the same battery of four 12-inch (305 mm) guns. She also carried thinner armour, but incorporated new Krupp steel, which was more effective than the Harvey armour used in the Majestics. Canopus was laid down in January 1897, launched in October that year, and commissioned into the fleet in December 1899. Canopus served in the Mediterranean Fleet upon commissioning until 1903, when she was decommissioned for refitting. In 1905, she was sent to East Asia, but the renewal of the Anglo-Japanese Alliance that year rendered her presence in Asian waters unnecessary. She instead returned to Britain and served with several fleet commands in British waters, including the Atlantic Fleet, the Channel Fleet, and finally the Home Fleet. Another short deployment to the Mediterranean followed in 1908–1909. Upon returning to Britain, she was placed in reserve.
At the beginning of the First World War in August 1914, she was mobilised for service in the South America Station, where she patrolled for German commerce raiders. She was involved in the search for the German East Asia Squadron of Vice Admiral Maximilian von Spee. Too slow to follow Admiral Sir Christopher Cradock's cruisers, she missed the Battle of Coronel in November 1914, where Cradock was defeated. Moored at Port Stanley as a defensive battery, she fired the first shots of the Battle of the Falklands in December, which led Spee to break off the attack before being chased down and destroyed by Admiral Doveton Sturdee's battlecruisers. Canopus was transferred to the Mediterranean in early 1915 for the Dardanelles Campaign. She participated in major attacks on the Ottoman coastal fortifications defending the Dardanelles in March 1915, but the British and French fleets proved incapable of forcing the straits. After the Gallipoli Campaign ended with the withdrawal of Allied forces in January 1916, Canopus patrolled the eastern Mediterranean, but saw no further action. She was removed from service in April 1916 and was converted into a barracks ship in early 1918. After the war, the ship was broken up in 1920.