Bell was born in Ottawa, Ontario, Canada, and was working as a mechanical engineer on the outbreak of the war. He served in the Governor General's Foot Guards, before signing attestation papers for service overseas on 1 February 1915, and was assigned to the 38th Battalion, Canadian Expeditionary Force, with the rank of lieutenant. According to his service record his father was by then dead, so he gave his mother as his next of kin. The 38th Battalion remained in Canada until 14 August 1915, when it was transferred to Bermuda to serve as part of the garrison. In May 1916 it sailed for England, and served in France from 13 August, seeing action in the Battle of the Somme. On 2 January 1917 Bell was seconded to the Royal Flying Corps as an observer on probation, also being attached to the Eastern Ontario Regiment. After training in England, on 15 February he returned to France to serve in No. 22 Squadron RFC. He was also promoted to captain in the Eastern Ontario Regiment on 19 March. Flying in a F.E.2b two-seater Bell gained his first aerial victory on 8 April, with Lieutenant L. W. Beale as pilot, sharing with five other aircraft of his flight in the destruction of an Albatros D.II over Regny. On 3 May, with Second Lieutenant E. A. H. Ward as his pilot, he destroyed an Albatros D.III, and on 15 May his period of probation came to an end and he was appointed a flying officer with seniority from 9 January. On 29 July, Bell and Ward, destroyed an enemy two-seater over Tortequesne. Bell then returned to England to train as a pilot, attending the No. 1 School of Military Aeronautics at Reading from 13 August 1917, then being posted to No. 12 Training Squadron on 20 September, and to No. 83 Squadron RFC on 13 October. Within a week he was sent to Egypt, assigned to a Training Brigade, and completed a course in aerial gunnery at the Aerial Fighting School at RFC Heliopolis. On 19 December 1917 Bell was appointed a flying officer, with seniority from 9 January. He was sent to Salonika to join No. 47 Squadron RFC operating on the Macedonian front. On 13 April 1918, flying a S.E.5a single-seat fighter, he destroyed an Albatros D.III. Bell was promoted to the temporary rank of captain on 13 June, to serve in a new unit, No. 150 Squadron RAF, formed from flights detached from No. 47 and No. 17 Squadrons. There Bell gained the remainder of his victories, accounting for twelve more enemy aircraft between 13 May and 18 September 1918. On 2 November 1918 he was awarded the Distinguished Flying Cross. His citation read: On 29 February 1919 Bell appeared before a Medical Board, having contracted malaria in Salonika in September 1918; he suffered from intermittent fevers, weakness, and insomnia, and was assessed as being unfit for further service. On 6 May Bell ceased to be seconded to the RAF, relinquishing his commission. On 13 May he was demobilized from the Canadian Expeditionary Force. On 10 October 1919 he received unrestricted permission to wear the insignia of a Chevalier of the Legion of Honour, conferred on him by France.
