William Stanley Penhalluriack was born in Ballarat and was an Electrician when he enlisted in the Siege Artillery Brigade Reinforcement 3 on 7 September 1915 at the age of 19. His unit embarked from Sydney, New South Wales, on board HMAT A67 Orsova on 10 November 1915. He was awarded the Military medal for bravery in the field on 17 August 1917 before proceeding to England. According to his records he served the rest of his tour with no major incident, illness or injury, returning home to Australia aboard the H.T. Ajana. He received his full discharge on 9 December 1919.

His brother, Warrant Officer I Francis John Robert Penhalluriack, 21st Battalion, also served (Tree No. 3029)
Tree No. 3028