The Northern region of Nigeria is saddled with ethno-religious violence, land-related conflicts and militant incursions, often resulting in killings, internal displacements and widespread human suffering. This paper examined the causes and consequences of insecurity in Northern Nigeria between 2014 and 2024. Anchored on three interrelated theoretical frameworks, the social contract theory, failed state theory and frustration-aggression theory, the study employed a longitudinal survey design and utilised secondary data sourced from internet materials, media reports, academic journals, textbooks and government publications. Thematic content analysis was used to interpret the data. Findings revealed that insecurity in Northern Nigeria stems from a complex interplay of socio-economic, political and structural factors, including corruption, conflict entrepreneurship, religious extremism, ethno-religious tensions, porous borders, arms smuggling, financial inducement, competition over natural resources, political marginalization, poverty, unemployment and weak security infrastructure. These factors have collectively contributed to mass displacement, economic disruption, food shortage, school closures and a breakdown in social cohesion and public order. The study recommended strengthening security institutions, investing in youth empowerment, addressing systemic poverty and promoting inclusive governance as strategies to mitigate the root causes of violence and insecurity. The originality of this study lies in its decade-long analytical synthesis of precipitating factors and implications of insecurity in the Northern part of Nigeria, offering an integrative theoretical and empirical contribution to the discourse on national security. Further research is suggested to explore community-led peacebuilding models and the long-term psychological impacts of chronic insecurity on affected populations.