Flemming’s birth was registered at Cooma NSW in 1884. He enlisted at Warialda on 12 January 1916 when he stated that he was a single man, aged thirty three, and working as a Labourer. He had previously tried to enlist at Liverpool NSW in November 1914. With eleven other Warialda district men he joined with the Inverell volunteers known as the First Contingent of The Kurrajongs on their journey to the Narrabri and Armidale Camps.
He became a member of the 33rd Battalion C Company and trained at Armidale and Rutherford prior to sailing from Australia on the ship HMAT A74 Marathon in May 1916. After nine weeks at sea the Battalion arrived in England where further training was undertaken at Salisbury Plain before they were sent to France in November.
Flemming was wounded in action in July 1917 and transferred to England where he was admitted to 1st Southern General Hospital with gunshot wounds to both legs. At the beginning of 1918 he sailed home and was medically discharged in May. During the 1930s and 1940s he lived in the Mudgee district of NSW and died at Cassilis in 1951.
Private Flemming O’Neill’s name is recorded on the Honor Roll at the Warialda Town Hall.