In order to achieve sustainable development and a consequent reduction in levels of poverty, a multisectoral response to development incorporating pro-poor economic policies in low- to middle-income countries (LMICs) is required. An important aspect is strengthening the human capital asset base of vulnerable populations. This should include the promotion of mental health, which can play an important role in breaking the intergenerational cycle of poverty and mental ill-health through promoting positive mental health outcomes within the context of risk. For each developmental phase of early childhood, middle childhood and adolescence, this article provides: (i) an overview of the critical risk influences and evidence of the role of mental health promotion initiatives in mediating these influences; (ii) a background to these risk influences in South Africa; and (iii) a review of mental health promotion initiatives addressing distal upstream influences at a macro-policy level in South Africa, as well as evidence-based micro- and community-level interventions that have the potential to be scaled up. From this review, strengths and gaps in existing micro- and community-level evidence-based mental health promotion interventions as well as macro-policy-level initiatives are identified, and recommendations made for South Africa that may also have applicability for other LMICs.