Keith Rourke was born in 1887 at Singleton, New South Wales to parents Henry and Amy Rourke. He enlisted in the Australian Imperial Force on 28 August 1914, joining the 2nd Infantry Battalion. Prior to enlistment, Rourke worked as a farmer on his father s property, 'Cheshunt', near Singleton. He departed Sydney on 18 October 1914 aboard HMAT Suffolk and joined the preparations for the Gallipoli landing in Alexandria.

Rourke survived the landing only to suffer a shoulder wound in early May which was compounded by his contracting influenza whilst in hospital on Mudros Island. He was invalided to England in September and remained there until March 1916, when he re-joined his unit in France. By mid-1917, Rourke had been promoted to corporal but was suffering a shrapnel wound to the back and trench foot.

Whilst recovering, Rourke trained in musketry at the Lewis Gun School of Instruction in Tidworth. In October 1918 Rourke was promoted to sergeant, but was returned to Australia on special leave before the end of the war. Keith Rourke also served in the Second World War, listing his date of birth as 1891 in order to serve.