With the outbreak of World War I, the University Council appointed a Committee on Military Instruction which authorized the teaching of military science and tactics. A university corps was organized in the fall semester of the 1914-1915 year with 64 students taking extra classes to qualify as officers. On March 1, 1915, the Canadian Officers Training Corps (C.O.T.C.) of the University of Manitoba was established. Eight companies of 60 men of all ranks were formed with Professor E.P. Fetherstonhaugh as captain and adjutant. In 1915, the Western Universities Battalion was formed with the University of Manitoba contributing one company and one platoon. With the introduction of conscription legislation in 1917, military training was made compulsory for all male students. After the First World War, the C.O.T.C. program was reorganized, in 1920, by Lt. Col. N.B. Maclean, but it continued in relative obscurity for almost twenty years.

With the outbreak of World War II, the C.O.T.C. was quickly revitalized and its membership mushroomed, from its peace time level of 150 to 800. The Senate also passed regulations relating to academic credits or bonuses for students who joined the C.O.T.C. By 1942, all male students were once again required to enlist in a compulsory programme of military training. The C.O.T.C. continued the work of military training on a voluntary basis after World War II with new modernized and attractive programmes, but with the return of peace its popularity rapidly declined.