Air Chief Marshal Sir Arthur Murray Longmore, GCB, DSO, DL (8 October 1885 – 10 December 1970) was an early naval aviator, before reaching high rank in the Royal Air Force. He was Commander-in-Chief of the RAF's Middle East Command from 1940 to 1941.
Born in Manly, New South Wales, the son of Charles Croker Longmore and Janet Murray, he was educated at Benges School, Hertford and Foster's Academy, Stubbington before entering Dartmouth Naval College. He was commissioned into the Royal Navy in 1904. Having developed an interest in flying, he volunteered for pilot training when the Navy accepted an offer of training facilities by the Royal Aero Club, and was one of the four officers to be selected. He obtained flying certificate No.72 in April 1911. That year, assisted by Oswald Short of Short Brothers, he devised a way of mounting streamlined air bags on the undercarriage struts and under the tail of an Short Improved S.27 biplane with the construction number S.38—later often referred to as the "Short S.38"—and on 1 December 1911, using the air bags for flotation, then-Lieutenant Longmore became the first person in the United Kingdom to take off from land and make a successful water landing in a seaplane when he landed Improved S.27 No. 38 on the River Medway off Sheerness.