Despite theoretical and policy advancements in global human and gendered approaches to development, youth in mainstream development policy discourse remains subsumed. The ratification of global best practice models of human development in Nigeria, without contextualizing the probable dividends of youth capability strength in shaping national development realities, will present challenges that are likely to threaten the sustainable future of country. Perhaps if this is sustained, this thesis argues that the capabilities of Nigerian youths will continue to remain trapped or mismatched in areas that they fail to contribute positively to Nigeria's national development. In this regard, this thesis evaluated the extent to which youth capabilities are enhanced in the National Youth Service Corps (NYSC) for national development in Nigeria. Firstly, this thesis contributes conceptually to understanding, broadly, the social constructions of youth in mainstream policy discourse and their positioning in both global and national development practice in Nigeria. It also critically examines through literature how western epistemological interpretations of development theorizing are reproduced in youth discourse. Succinctly, the theoretical contribution of youth in development explains how development-underdevelopment dualism in mainstream development reproduces similar youth-adult dualisms in conceptualizing how youths are recognized, represented and constituted within policy discourses. Based on this, the theoretical gaps that this thesis bridges, operationalizes the Sen's capability approach (SCA) through the utilization of Narayan-Parker's empowerment framework in order to contextualize how the intersections of youth agency and structural contributions of the NYSC could aid the effective utilization of youth capabilities for national development in Nigeria. Secondly, this thesis contributes methodologically to development practice as it adapts a mixed-method approach (MMA) to researching youth lives, especially from a developing country's context. The application of a qualitative dominant mixed method approach (qual-MMA), suggests how through social constructivist ontology and through poststructuralist epistemology, the understanding of how youths socially construct their identity and the roles they play in national development becomes clearer. Thirdly, the germane and empirical contribution of this thesis especially to mainstream development theorizing is that, youth voices captured through narratives and quantitative data helped explore the experiences of Nigerian youth's transition pathways from education to the NYSC pathway. This further allowed for critical examination of how youths are: absorbed through mobilization into the NYSC; developed through the activities in the scheme; deployed and utilized in addressing national development challenges in Nigeria. This thesis suggests that dominant social constructions based on age and transition patterns, undermine the impact/effective functioning of youth capabilities for addressing national development challenges. It concludes that limited support structures during the youth educational pathways and lack of opportunity structures while youths are in the NYSC pathways continue to limit the functioning of their capabilities in sectors of national development needs. It recommends a need to rethink the current deployment strategy of the NYSC so that youth capabilities fit the national development narrative.