John McMillan Cox (SN 4166) was born in Warrnambool, Victoria, but was working as a labourer in Ballarat when he enlisted there, alongside his son Clarence, on July 6th 1915. The 44 year old embarked from Melbourne with Clarence on board the Demosthenes at the end of December. There are some gaps in his record but it appears that, although spending some time with the 4th Training Battalion in England, he was never deployed to the battlefield and returned to Australia on board the Suevic in November 1917. A medical board found he was suffering from 'senility and debility' and he was discharged as medically unfit on December 28th 1917.

His three sons, Clarence, Norman and Ernest also served in the AIF and are honoured with trees in the Avenue.