 On 7 February 1916 Fairclough was commissioned as a lieutenant in the 2nd Regiment, Queen's Own Rifles of Canada.On 24 May he volunteered for overseas service, and was assigned to the 166th Battalion, Canadian Expeditionary Force.He sailed for England on 26 September, and on 6 October was placed on the General List, assigned to the Canadian Machine Gun Corps, and posted to the Canadian Training Depot.