People-centered care has emerged as a transformative approach to healthcare that emphasizes the active involvement of individuals, families, and communities in health promotion and service delivery. Social workers play a central role in advancing this approach by addressing the social determinants of health, facilitating access to healthcare services, promoting healthy behaviors, and advocating for vulnerable populations. This paper examined the role of social workers in promoting people-centered care through health promotion and its contribution to national development in Nigeria. The study adopted a narrative literature review design, drawing on recent empirical and theoretical literature published between 2020 and 2026 from peer-reviewed journals, reports, and policy documents. The review revealed that social workers contribute significantly to health promotion through health education, psychosocial support, community mobilization, case management, advocacy, and policy development. These interventions improve health literacy, encourage preventive healthcare practices, reduce health inequalities, strengthen primary healthcare systems, and enhance community participation in healthcare decision-making. The findings further indicate that effective health promotion contributes to improved human capital development, increased workforce productivity, reduced healthcare costs, poverty reduction, and sustainable national development. Despite these contributions, challenges such as inadequate professional recognition, limited integration of social workers into healthcare teams, insufficient government support, and weak policy implementation continue to constrain the effectiveness of social work practice in Nigeria. The paper concludes that strengthening the integration of social workers within people-centered healthcare systems is essential for improving population health and achieving sustainable national development. It recommends increased government investment in social work services, improved professional regulation, expanded deployment of social workers across healthcare facilities and communities, and stronger multisectoral collaboration to maximize the contribution of social workers to health promotion and national development.