Admiral of the Fleet Sir Osmond de Beauvoir Brock, GCB, KCMG, KCVO (5 January 1869 – 15 October 1947) was a Royal Navy officer.

Following the Turkish victory in Anatolia at the end of the Greco-Turkish War, Brock organised the rescue of fleeing Greek civilians and, by skillful deployment of his ships, he dissuaded the advancing Turks, led by Mustafa Kemal Atatürk, from attacking the British garrison at Chanak in the Dardanelles neutral zone.

[7] Promoted to lieutenant, after first classes in every subject and maximum seniority, on 14 February 1889,[8] Brock joined the battleship HMS Trafalgar, flagship of the Second-in-Command of the Mediterranean Fleet, in April 1890.

[7] Appointed a Companion of the Order of the Bath on 3 March 1915 and promoted to rear admiral two days later,[16][17] he became commander of the 1st Battlecruiser Squadron with his flag in HMS Princess Royal and saw action in that capacity at the Battle of Jutland in May 1916.

[18] At Jutland, Brock played an important role repeating messages from Vice Admiral Sir David Beatty, Commander of the Battlecruiser Fleet, whose radio was out of action.

[22] Brock became Deputy Chief of the Naval Staff and a Lord Commissioner of the Admiralty in July 1919 with promotion to vice admiral on 3 October.

[18] Following the Turkish victory in Anatolia at the end of the Greco-Turkish War in August 1922, Brock organised the rescue of the fleeing Greek army and, by skilful deployment of his ships, he dissuaded the advancing Turks, led by Mustafa Kemal Atatürk, from attacking the British garrison at Chanak in the Dardanelles neutral zone in September.

[24] For his diplomatic handling of the Chanak Crisis, Brock was commended by Leo Amery, the First Lord of the Admiralty, in the House of Commons in 1923.