Adrian John Liddell Hart (1922–1991) was a British soldier, Royal Navy officer, Liberal politician, author and adventurer. He served briefly in the French Foreign Legion and portrayed it in the 1953 book Strange Company.
The son of Sir Basil Liddell Hart (1895–1970), by his first wife Jessie Stone, Hart was the godson of Major-General J. F. C. Fuller and was educated at St Andrew's School, Pangbourne, before Eton and King's College, Cambridge. With the outbreak of the Second World War in 1939 he joined the British Army and in 1940 became adjutant of the Local Defence Volunteers at Dartington, Devon. In 1941 he joined the trained Royal Naval Volunteer Reserve and after training at HMS Collingwood, Fareham, he was selected as an officer candidate. After obligatory sea time as a junior rank on the Flower-class corvette Carnation during which he saw service in the Battle of the Atlantic, he was commissioned and attended the RNVR officer training course at HMS King Alfred in Hove, Sussex. He was promoted to sub lieutenant in HMS Jamaica in 1942 and saw active service in the Mediterranean in 1943, before joining the Combined Operations Command of British North African Forces later that year and the Signal Division of the Admiralty in London from 1943 to 1944, then HMS Coldstreamer and HMS Guardsman later in 1944. In 1945 he was appointed flag lieutenant to the admiral commanding Iceland.