The well-being and development of Girls, Boys, Adolescents, and Youth (GBAY) in Latin America are not only fundamental to the region’s economic and civic progress but also to its social fabric and collective future. This chapter presents a multiprofessional approach to fostering sustainable development for GBAY, built upon three interdependent axes: the life cycle, multidimensionality, and the pivotal role of significant adults. We explore the biological and socio-historical foundations shaping their development, emphasizing the delicate balance between genetic potential and environmental influences. Furthermore, we examine the profound impact of stress—particularly toxic stress—on neurodevelopment and well-being, highlighting the essential protective role of caring, engaged adults. From a socio-historical perspective, we analyze how childhood and adolescence are shaped as social constructs, underlining the importance of identity, belonging, and citizenship. Democratic participation emerges as both a fundamental right and a pathway to empowerment, aligning with the principles of the United Nations Convention on the Rights of the Child. Through case studies, such as participatory budgeting in Montevideo, we illustrate how structured civic engagement fosters agency and strengthens democratic institutions. Additionally, we address challenges in higher education, particularly for young women navigating the demands of academia alongside pregnancy and motherhood. We advocate for institutional policies that genuinely support student parents, ensuring educational continuity and promoting equitable human capital formation. Ultimately, we offer actionable recommendations to cultivate environments where GBAY can flourish. By aligning policies, educational strategies, and adult support networks, Latin American societies can create sustainable, inclusive pathways for youth development—ensuring not only personal growth but a shared, hopeful future.