This chapter describes adolescent development within the context of capacity building, reviews the global adolescent capacity-building initiatives, and provides a link between developmental tasks of adolescence and capacity building. It highlights the importance of incorporating assessment of adolescents’ capacity-building needs at individual, community, and organizational levels into global policy and programs and suggests effective approaches to building adolescent development capacity that include adopting the “stage–environment–fit,” in which stage represents the developmental stages (early, middle, late stages) of adolescents and emphasizes developmental tasks of adolescence, while environment represents the social and cultural contexts in which the adolescents live. That adolescents need to be engaged as planners, decision-makers, and participants in programs that build their capacity and translation of global policies into policies of governments is emphasized.