Sidney, a son of Thomas and Emily Gray, was born at Bundarra NSW in 1884. He was a thirty-two-year-old Miner at Elsmore NSW when he enlisted at Inverell in August 1915 and went to the Narrabri Depot Camp. He joined the 30th Battalion, 3rd Reinforcement and departed Australia for Egypt on HMAT A 70 Ballarat in February 1916. He served at Ferry Post on the Suez Canal until transferred to France in July 1916.
Sidney was wounded in action in November 1917 and sent to England. He was hospitalised at the 1st London General Hospital and treated for a gun shot wound to his arm. The following April he returned to his unit in France.
At the end of the War Sidney came back to Australia where he was medically discharged in August 1919. By 1930 he was working as a Miner at Cessnock NSW where his lived until his death in 1968.