During the Second World War, training was the Canadian Army’s longest sustained activity. Aside from isolated engagements at Hong Kong and Dieppe, the Canadians did not fight in a protracted campaign until the invasion of Sicily in July 1943. The years that Canadian infantry units spent training in the United Kingdom were formative in the history of the Canadian Army. Despite what much of the historical literature has suggested, training succeeded in making the Canadian infantry capable of succeeding in battle against German forces. Canadian infantry training showed a definite progression towards professionalism and away from a pervasive prewar mentality that the infantry was a largely unskilled arm and that training infantrymen did not require special expertise. From 1939 to 1941, Canadian infantry training suffered from problems ranging from equipment shortages to poor senior leadership. In late 1941, the Canadians were introduced to a new method of training called “battle drill,” which broke tactical manoeuvres into simple movements, encouraged initiative among junior leaders, and greatly boosted the men’s morale. The Canadians participated in numerous military exercises of varying sizes that exposed problems with their senior leadership. The replacement of unsuitable officers greatly enhanced the fighting potential of Canadian units and formations. As time went on, infantry training became more rigorous and realistic, and tactical concepts became increasingly sophisticated. By the time of the invasion of Normandy in June 1944, infantry training was intense, suited to units’ assigned tasks, and highly technical, which belied the false prewar assumption that the infantry was an unskilled arm. By the time Canadian divisions entered battle, they were as prepared as they would ever be. The exception to this was the training of the overseas reinforcement units, which reached an acceptable standard only in the last months of the war. This study ultimately represents a substantial contribution to understanding the history of the Canadian Army and its role in the Second World War.