This book examines the growing phenomenon of armed banditry in Nigeria and its implication for national security. Nigeria's banditry crisis and deepening security challenges are fuelled by the existence of vast un(der)governed hinterland and trans-border spaces where various non-state armed groups operate unhindered and outside of the law, engaging in various forms of transnational crime. This book explores the activities of these groups to assess the nature and significance of banditry as a complex threat to security. It does so against the backdrop of reports of increased bandit attacks on farms, markets, mining sites, villages and rural communities, and the rising tide of violent crimes in Nigeria, especially the northern region. This book analyses the factors that are responsible for the emergence of banditry as a recent national and transnational security threat and outlines the contemporary dynamics of Nigeria's banditry crisis and how it can be mitigated. This book will be of interest to researchers and students in the field of African Studies, International Relations, Security and Strategic Studies, Political Studies, Peace and Conflict Studies, as well as policymakers and practitioners interested in complex security threats and their implications in Nigeria and beyond.