While studying at the University of Ottawa, Fernand Mousseau, from Hull enrolled in the Officer Training Corps in 1940 and was transferred to Le Régiment de Hull. He was promoted to Lieutenant at the Brockville training camp for officers and was transferred to the Officer Candidate School in Saint-Jérôme, Quebec. In 1942, Mousseau joined the Montreal unit, Les Fusiliers Mont-Royal, in order to help bring the decimated unit back up to strength following the disastrous Dieppe Raid.