Rear-Admiral Sir Samuel John Brooke Pechell, 3rd Baronet CB, KCH, FRS (1 September 1785 – 3 November 1849) was a prominent British Royal Navy officer of the early nineteenth century. Although he served in several celebrated naval actions of the French Revolutionary and Napoleonic Wars his most important achievements were made while serving as a Lord of the Admiralty, pioneering the science and instruction of rapid and accurate gunnery in the Royal Navy through training facilities and manuals.