Myall O'Mallee was educated at the Melbourne Christian Brothers' College and the Longerenong Agricultural College before studying Veterinary Science at Melbourne University. He enlisted in the A.I.F. in 1915 but was discharged, on medical grounds, two years later. Once he returned home he spent some time farming in the Mallee area before taking a position, as a health inspector, with the Federal Department of Commerce and Agriculture. O'Mallee was a fellow of the Bread and Cheese Club, Melbourne, and member of the Catholic Writers' Movement.