John was the son of John and Annie Gilbert of Bundarra NSW. His birth at Bundarra was registered at Inverell in 1884. Before the War he had worked as a Grocer for Pepper and Cutcher at Inverell, later managing their branch store at Howell.

At the age of twenty nine he enlisted in Sydney in September 1914, joining the 13th Battalion, C Company. With this Battalion he sailed from Australia for Egypt on HMAT A38 Ulysses in December 1914.

John served at Gallipoli where he was Killed in Action on 3 May 1915. He has no known grave and his name is recorded on the Lone Pine Memorial at Gallipoli, Turkey. His personal possessions, including a disc, purse, Rosary and wallet were returned to his sister Amy.