William Martin Phelan was born in Ballarat ad was a Packer living on Simpson Street, East Melbourne, Victoria when he enlisted in the 59th Battalion, 5th Reinforcement on 11 July 1916 at the age of 24. His unit embarked from Melbourne, Victoria, on board HMAT A9 Shropshire on 25 September 1916. He was transferred to hospital a sick on 15 April 1917, re-joining his unit on 15 August. He was again admitted to hospital on 4 Jan 1918 for a hernia and was temporally detached to the 5th A.D. Signal Company in February 1918. He returned to Australia 6 September 1919 and received a medical discharge on 20 October 1919.
Tree No. 2478