Field Marshal Sir John Greer Dill GCB, CMG, DSO (25 December 1881 – 4 November 1944) was a senior British Army officer with service in both the First World War and the Second World War. From May 1940 to December 1941 he was the Chief of the Imperial General Staff (CIGS), the professional head of the British Army, and subsequently in Washington, D.C., as Chief of the British Joint Staff Mission and then Senior British Representative on the Combined Chiefs of Staff (CCS), played a significant role during the Second World War in the formation of the "Special Relationship" between the United Kingdom and the United States.
Born in Lurgan, County Armagh, Ireland in 1881, his father was the local bank manager and his mother was a Greer from Woodville, Lurgan. Always intended for a career in the services, Dill attended the Methodist College Belfast,Cheltenham College and the Royal Military College at Sandhurst. On 8 May 1901 he was commissioned as a second lieutenant into the 1st battalion the Leinster Regiment and was posted to South Africa to see out the Second Boer War.