This study, titled Leadership and Development in Medical Tourism: Impact of the COVID19 Pandemic on Health Security in Nigeria, explores the role of leadership in shaping Nigeria’s medical tourism and health security during the COVID-19 pandemic. The study focuses on government policy responses and leadership decisions made to address the crisis. The primary objectives are: 1) to analyse the impact of the COVID-19 pandemic on medical tourism in Nigeria, 2) to identify the policy measures implemented by the Nigerian government, and 3) to assess the influence of the pandemic on Nigeria’s health security. Guided by the Contingency Theory of Leadership, which emphasises leadership effectiveness based on the specific challenges and context, this study adopts a qualitative methodology, utilising secondary data sources such as government reports, healthcare policies, expert analyses, and academic literature. Thematic analysis is applied to identify key themes related to policy responses, shifts in medical tourism, and their broader impact on health security. Findings reveal that the pandemic caused a significant decline in medical tourism, as global travel restrictions prompted many Nigerians to seek healthcare domestically. In response, the Nigerian government implemented policy measures to strengthen healthcare infrastructure, improve medical facilities, and address public health challenges. These efforts contributed to a positive shift in Nigeria’s health security, encouraging greater reliance on domestic healthcare and raising public health awareness. The study underscores the importance of robust leadership in managing crises and highlights the need for sustained investment in healthcare infrastructure. A key recommendation is for the Nigerian government to prioritise healthcare system development, improve medical infrastructure, reduce dependence on foreign healthcare, and invest in public health education to prepare for future health challenges.