The regiment mobilized a battalion for the Canadian Active Service Force in 1939. Initially organized as a machine gun battalion, the battalion was sent to England in August 1941. The unit was assigned to the 3rd Canadian Infantry Division as a standard rifle battalion and was designated as a reserve battalion during the D-Day landings in June 1944. Le Régiment de la Chaudière came ashore on the second wave at Bernières-sur-Mer after The Queen's Own Rifles of Canada, surprising the locals who hadn't expected to find francophone troops in the liberating forces. It was the only French-Canadian regiment to participate in Operation Overlord, and one of the few French-speaking units to come ashore that day alongside the bilingual The North Shore (New Brunswick) Regiment and the Free-French Commando Kieffer.