After the outbreak of war in 1939, he was attested to the Canadian Active Service Force and promoted to the rank of major.

When the active component of his regiment was redesignated to become an Anglophone armoured unit, he requested a transfer to the infantry and became the Deputy Commanding Officer of Régiment de la Chaudière in England.

[2] He was in command of the 6th Canadian Infantry Brigade at the end of the war in Germany, in the rank of brigadier (now brigadier-general).

[4] He was the Canadian military attaché in Moscow after the war until 1948 when he was appointed Commander for the East Quebec Area.

The Général-Jean-Victor-Allard Building, the home of the Canadian Forces Leadership and Recruit School, was named in honour of General Allard.