The 18th Battalion (Western Ontario), CEF, was an infantry battalion of the Canadian Expeditionary Force in the Great War. The Battalion was authorized on 7 November 1914 and embarked for Great Britain on 18 April 1915. It disembarked in France on 15 September 1915, where it fought as part of the 4th Infantry Brigade, 2nd Canadian Division in France and Flanders until the end of the war. The battalion was disbanded on 15 September 1920.
The 18th Battalion recruited and was mobilized in London, Ontario.
The 18th Battalion had four Officers Commanding:
One member of the 18th Battalion, Lance-Sergeant Ellis Wellwood Sifton was posthumously awarded the Victoria Cross for his actions on 9 April 1917 during the assault on Vimy Ridge.
The 18th Battalion was awarded the following battle honours:
The 18th Battalion (Western Ontario), CEF, is perpetuated by The Essex and Kent Scottish .