Field Marshal Sir Claude John Eyre Auchinleck, The Auk, (June 21 1884 - 1981) was a British army commander during World War II.

Born in Aldershot and a graduate of Sandhurst, Field Marshal Auchinleck was a career soldier who spent much of his military career in India.

During World War II Auchinleck was given command of the Allied forces in Norway in May 1940. After the fall of Norway, in July 1940 he became briefly General Officer Commanding-in-Chief, Southern Command, and then Commander of the Indian Army.

He succeeded Field Marshal Archibald Wavell as C-in-C of the Allied forces in the Middle East in July 1941 on Wavell's appointment as Viceroy of India. Initial success at to El Agheila (January 1942) was followed by defeat by Rommel at Bir Hacheim (June 1942). Auchinleck withdrew his forces 400km back into Egypt; Tobruk fell on 21 June but the German/Italian advance was halted at the First Battle of El Alamein by the Eighth Army. The Auk, as he was known to his troops, was unfortunate in some of his subordinate senior officers in North Africa: some were incompetent, some were killed and some were captured; this resulted in Auchinleck being overwhelmed by the dual role of theatre C-in-C and field commander of the Eighth Army. He was sacked by Churchill in August 1942, reputedly because he refused to be bullied by Churchill into ordering a major offensive before he and his troops were properly prepared, and was replaced by William Gott, who was killed before he reached Egypt, and then General Harold Alexander with General Bernard Montgomery becoming commander of the Eighth Army. Auchinleck's reputation subsequently suffered unfairly at the hands of the Montgomery publicity machine: Montgomery launched his El Alamein offensive even later than the date proposed by Auchinleck while still in command.

In 1943 he return to India to become C-in-C of the British forces there. He also helped prepare the future Indian and Pakistani armies prior to Partition in August 1947. In 1946 he was promoted to field marshal but refused a peerage. He retired in 1947. Although a somewhat dour character, he was a soldier of the utmost integrity who was popular with his troops. In retirement, he moved to Marrakesh, where he lived quietly for many years, attended by a former soldier, up to his death in 1981.