This study investigated the complex security and development challenges arising from rapid urbanization and internal labour migration in Abuja, Nigeria. Employing a descriptive survey research design with a sequential explanatory approach to examine migration patterns, living conditions, and security dynamics. The study was conducted in the Federal Capital Territory, focusing on both formal districts (Asokoro, Maitama) and informal settlements (Nyanya, Karu, Kubwa). From a target population of approximately 850,000 adult residents, a multi-stage sampling technique was employed, incorporating stratified sampling to ensure proportional representation of settlement types and systematic random sampling to select 450 households (determined with 95% confidence level and 5% margin of error, adjusted for non-response). Data collection involved structured questionnaires administered to households to gather quantitative data on demographic profiles, migration history, safety perceptions, and crime experiences, supplemented by systematic review of policy documents and urban development plans. Quantitative data were analyzed using statistical software (SPSS) to generate descriptive statistics and inferential analyses, while document analysis provided policy context and institutional insights. The findings revealed that economic factors (87.3%) and regional insecurity (42.1%) serve as primary drivers of migration, resulting in the proliferation of informal settlements characterized by severe service delivery gaps. These conditions correlate strongly with elevated crime rates, as residents of informal settlements reported significantly higher experiences of property crime (68.3% vs 15.2%) and violent crime (42.7% vs 8.3%) compared to formal districts. Crucially, the study identifies a crisis of institutional legitimacy, with only 18.4% of informal settlement residents expressing trust in police forces, highlighting the limitations of current enforcement-oriented security approaches. The research concluded that urban insecurity in Abuja is fundamentally rooted in governance failures, spatial inequality, and socioeconomic exclusion rather than mere law enforcement deficiencies. The study recommended that: implementing an integrated urban development framework, adopting community-centered policing strategies, enhancing livelihood opportunities for youth, and strengthening institutional coordination.