Psychology has long contributed to mental health, behavior change, and patient engagement, yet its potential in global health governance, policy, and systems strengthening remains underutilized. This chapter calls on psychologists and social scientists to take leadership roles in addressing global health challenges by applying their expertise in behavior change, stakeholder engagement, health equity, and digital health innovation. Key areas of impact include integrating psychological principles into public health policies, community-based interventions, and interdisciplinary collaborations. By tackling issues such as mental health disparities, vaccine hesitancy, and climate-related health risks, psychologists and social scientists can drive systemic change and improve health outcomes. The chapter also highlights emerging career opportunities in humanitarian psychology, health technology, and global health advocacy. Ultimately, it emphasizes the need for psychologists and social scientists to move beyond traditional roles and actively shape a more equitable and sustainable future for global health.