Admiral of the Fleet Sir Henry Leach, GCB, DL (born 1923) is a former First Sea Lord of the Royal Navy. Sir Henry Leach was First Sea Lord and Chief of the Naval Staff between 1979 and 1982. He was the professional head of the Royal Navy at the time of the Falklands War and was instrumental in convincing the Prime Minister Margaret Thatcher that retaking the islands was possible.
On 31st March 1982, soon after the Argentinian invasion of the Falklands, he brushed aside serious doubts from the Secretary of State for Defence Sir John Nott, and marched into visit the Prime Minister in full uniform. He was asked if retaking the islands was possible, he replied "Yes we can recover the islands." He then added "and we must!" Thatcher replied "Why?" he replied "because if we don’t do that, in a few months we will be living in a different country whose word will count for little!" This pleased Thatcher who then proceeded to give the order for the task force to set sail to retake the Falklands.
The Falklands campaign was successful, in no small part, thanks to Sir Henry Leach among others. He was promoted to Admiral of the Fleet upon retirement in late 1982.