Responding to security scholars’ puzzling dearth of attention to children and childhoods, the contributors to this volume reveal the ways in which they not only are already present in security discourses but are actually indispensable to them and to the political projects they make possible. From zones of conflict to everyday life contexts in the (post)industrial Global North, dominant ideas about childhood work to regulate the constitution of political subjects whilst variously enabling and foreclosing a wide range of political possibilities. Whether on the battlefields of Syria, in the halls of the UN, or the conceptual musings of disciplinary Security Studies, claims about or ostensibly on behalf of children are ubiquitous. Recognizing children as engaged political subjects, however, challenges us to bring a sustained critical gaze to the discursive and semiotic deployments of children and childhood in projects not of their making as well as to the ways in which power circulates through and around them. This book was originally published as a special issue of Critical Studies on Security.