The Fourth Sea Lord and Chief of Naval Supplies originally known as the Fourth Naval Lord was formerly one of the Naval Lords and members of the Board of Admiralty which controlled the Royal Navy of the United Kingdom the post is currently known as Chief of Materiel (Fleet). As of 2017, it is also known as Chief of Fleet Support, Chief of Materiel (Ships) then as of 2020, Director General Ships.

Rear-Admiral Sir Samuel John Brooke Pechell, 3rd Baronet CB, KCH, FRS 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.