Assigned to
16th Battalion as a
private, O'Meara sailed from Fremantle on the troopship
Ajana on 22 December 1915. He arrived at Port Suez in Egypt on 13 January 1916. He initially served with the 16th Battalion in Egypt as an infantryman and as a machine gunner with the 4th Machine Gun Company before arriving in France on 7 June 1916. In late June 1916 he joined the 16th Battalion's newly formed Scouting Section in northern France and served as a scout, observer and sniper during his time on the Western Front in Belgium and France. Between 9 and 12 August 1916 at Mouquet Farm,
Pozières, during four days of very heavy fighting, Private O'Meara repeatedly went out and brought in wounded officers and men from "
no man's land" under intense
artillery and
machine-gun fire. He also volunteered and carried up ammunition and bombs through a heavy barrage to a portion of the trenches which was being heavily shelled at the time. O'Meara was wounded three times during the war: near Mouquet farm in August 1916, near Bullecourt in April 1917 and near Messines in August 1917. He was presented with his Victoria Cross medal by King George V at Buckingham Palace on 21 July 1917. In mid-1918 he was selected to join a group of Australian Victoria Cross recipients to return to Australia to assist with recruiting. He was promoted to Sergeant in late August 1918 and left England on 17 September 1918 on the troopship
Arawa, arriving at Fremantle in Western Australia on 6 November 1918. On 7 November 1918 the
Arawa passengers were quarantined at Woodman's Point south of Perth because of a suspected influenza outbreak. , following the fighting at
Pozières ==Later life==