This dissertation investigates the motivations, messages, and methods of Canadians who organized in opposition to nuclear weapons between 1959 and 1963. The efforts of Canadian anti-nuclear movements have been undervalued in histories of disarmament activism. Canadian disarmers have been dismissed as quiet in comparison to better-known movements in the United States and in Great Britain. This dissertation demonstrates that there were in fact complex and vigorous expressions of anti-nuclear sentiment in Cold War Canada. Canadian disarmers may have been few in number, and may have been conservative in their protest methods, but they were committed participants in an international struggle to protect humanity from the threat of nuclear war. There were many Canadian movements in opposition to the Bomb, both organized and disorganized, which were shaped by the diverse relationships that disarmers had to the world around them. Disarmers’ endeavours were informed by engagements with feminisms, Western ideals of masculinity, parents’ desires to protect their children, young people’s hopes to inherit a world of peace and prosperity, longstanding ideas about social protest, concerns over domestic politics, and enthusiasm for international cooperation. Focusing on the various ways in which Canadians worked for disarmament in the early 1960s, this study demonstrates how much often divided and sometimes isolated disarmament organizations shared. This dissertation is the first extended historical analysis of anti-nuclear efforts in Canada in the late 1950s and early 1960s. It is also a necessary revision of the existing historiography on disarmament activism. This dissertation brings together diverse literatures on Canada’s Sixties; American, British, and Western European disarmament and peace movements; connected social movements such as the New Left, feminist movements, and environmental movements; and histories of children and childhood. The thesis offers a reassessment of these movements and their importance to an understanding of Cold War social and political dynamics.