Admiral of the Fleet David Richard Beatty, 1st Earl Beatty, was a Royal Navy officer. After serving in the Mahdist War and then the response to the Boxer Rebellion, he commanded the 1st Battlecruiser Squadron at the Battle of Jutland in 1916, a tactically indecisive engagement after which his aggressive approach was contrasted with the caution of his commander Admiral Sir John Jellicoe. He is remembered for his comment at Jutland that "There seems to be something wrong with our bloody ships today", after two of his ships exploded. Later in the war he succeeded Jellicoe as Commander in Chief of the Grand Fleet, in which capacity he received the surrender of the German High Seas Fleet at the end of the war. He then followed Jellicoe's path a second time, serving as First Sea Lord—a position that Beatty held longer than any other First Sea Lord. While First Sea Lord, he was involved in negotiating the Washington Naval Treaty of 1922 in which it was agreed that the United States, Britain and Japan should set their navies in a ratio of 5:5:3, with France and Italy maintaining smaller ratio fleets of 1.75 each.

Admiral of the Fleet is a five-star naval officer rank and the highest rank of the Royal Navy, formally established in 1688. The five-star NATO rank code is OF-10, equivalent to a field marshal in the British Army or a Marshal of the Royal Air Force. Apart from honorary appointments, no new admirals of the fleet have been named since 1995, and no honorary appointments have been made since 2014.