John was the son of Thomas McInerney of Green Rock, Hinton, NSW. When he enlisted at Bathurst NSW in June 1916, he stated he was a twenty nine year old single man, and that he was a School Teacher.

John joined the 54th Battalion, 6th Reinforcement and whilst in camp at Bathurst was hospitalised with mumps. He sailed from Australia on the ship HMAT A40 Ceramic in October 1916 arriving in England six and a half weeks later. His Battalion was then sent to France in December. 

After enduring the freezing winter conditions, John was Killed in Action on 15 May 1917 at Bullecourt, France. He has no known grave and his name is recorded on the Australian National Memorial at Villers-Bretonneux, France.

John had made a will leaving his estate to his sister Katherine. His personal effects, which included discs, wallet and letters were returned to his father at Hinton.

Before the War, John had been a teacher at Bonshaw Public School, north of Inverell. His name is recorded on the Hinton Public School Memorial Gates.