The Niger Delta crisis, characterized by militant insurgency, oil theft, and environmental degradation, poses significant threats to Nigeria's national security. The region's instability has far-reaching consequences, affecting not only the local population but also the country's economy, politics, and international relations. This paper examines the impact of the Niger Delta crisis on national security, exploring the historical context, key drivers of the conflict, and its manifestations. The study analyzes the consequences of the crisis on Nigeria's economic, political, and social stability, as well as its regional and global implications.