Sustainable national development extends beyond economic growth and technological advancement; it also depends on the psychological well-being and ethical orientation of leaders and citizens. In Nigeria, persistent challenges such as corruption, weak institutional accountability, declining public trust, and poor leadership outcomes underscore the need for a psychologically informed approach to governance and national transformation. This paper examines how psychological well-being can be strategically re-engineered to foster ethical leadership and accelerate sustainable national development
through the integration of psychological science, professional practice, and emerging technologies. Drawing on Positive Psychology, Emotional Intelligence Theory, Transformational Leadership Theory, and Digital Psychology, the paper argues that psychologically healthy leaders are more likely to demonstrate integrity, resilience, empathy, accountability, and sound decision-making—qualities essential for effective governance and institutional performance. It further explores the transformative potential of artificial intelligence, digital mental health platforms, and technology-assisted psychological interventions in leadership assessment, emotional regulation, capacity building, and organizational effectiveness. While recognizing the ethical challenges associated with emerging technologies, the paper contends that their responsible application can enhance psychological practice and leadership development across public, educational, faith-based, and corporate sectors. Adopting a conceptual and interdisciplinary approach, the study concludes that integrating psychological science, evidence-based practice, and responsible technological innovation provides a practical pathway for developing resilient, ethical, and socially responsible leaders capable of driving national transformation. It recommends increased investment in psychological services, technology-enabled mental health interventions, leadership development programmes, and evidence-informed public policies that position psychological well-being as a strategic asset for sustainable national development.