Admiral of the Fleet John Cronyn Tovey, 1st Baron Tovey,, sometimes known as Jack Tovey, was a Royal Navy officer. During the First World War he commanded the destroyer HMS Onslow at the Battle of Jutland and then commanded the destroyer Ursa at the Second Battle of Heligoland Bight. During the Second World War he initially served as Second-in-Command of the Mediterranean Fleet in which role he commanded the Mediterranean Fleet's Light Forces. He then served as Commander-in-Chief of the Home Fleet and was responsible for orchestrating the pursuit and destruction of the Bismarck. After that he became Commander-in-Chief, The Nore with responsibility for controlling the east coast convoys and organising minesweeping operations.

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.