Adolescents in international secondary schools develop their social lives across culturally diverse campuses and digitally connected peer networks. Although friendship quality, social media use, and adolescent well-being have each received substantial attention, the mechanisms through which offline and online social experiences jointly relate to social well-being remain conceptually fragmented. This structured conceptual review develops an integrated framework for international secondary school students in Malaysia. The framework is informed by the relatedness branch of Self-Determination Theory and the resource-exchange logic of Social Exchange Theory and proposes that peer relationship quality and meaningful social media use relate to social well-being via relatedness need satisfaction, perceived social support, and psychological resilience. Gender and cultural identity are conceptualised as contextual moderators rather than universal determinants. The review employs a transparent, purposive search and synthesis process, and differentiates the framework from previous reviews on friendship quality, social media use, or Self-Determination Theory as isolated constructs. This paper contributes by integrating offline and online social contexts, elucidating complementary motivational, resource and adaptive pathways, and situating these relationships within Malaysian international schools, where foreign curricula, English medium instruction, mixed nationalities, student mobility and cultural identity negotiation may shift the salience and strength of otherwise general adolescent mechanisms. The propositions are untested and are therefore offered as theoretically grounded expectations rather than empirical conclusions. The framework offers a focused agenda for longitudinal, multilevel, cross-cultural and intervention research and offers cautious guidance for school-based belonging, peer-support, resilience and digital citizenship initiatives.