Security has always been a core function of the modern state. Yet the rise of the Preventive State captures an intensification of that role as threats to security and demands for public protection increase, prompting states to prioritize new practices of preventive criminalization, policing, and punishment. The rise of the Preventive State may promise greater security, but the costs of ever more coercive preventive laws and measures are burdensome and pose a threat to civil liberties. This review considers the drivers, multiple manifestations, and direct and collateral consequences of preventive endeavors that assess and manage risk, target hazards, and restrain or detain those deemed dangerous. It also explores their ramifications for criminology and criminal justice. It concludes by considering the potential of criminology to join cross-disciplinary efforts to articulate a new jurisprudence of security and to elaborate principles of preventive justice with which to restrain the excesses of the Preventive State.