This book examines the development of Japan’s human security diplomacy for global health in the pre- and post-COVID-19 world. In the light of global health politics and human security studies, it attempts to clarify Japan’s financial and diplomatic contributions to the Gavi, the Vaccine Alliance (Gavi), the COVID-19 Vaccines Global Access (COVAX) Facility, the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund), the Global Polio Eradication Initiative (GPEI), the Tokyo International Conference on African Development (TICAD), official development assistance (ODA) related to global health, the Global Health Innovative Technology Fund (GHIT Fund) to combat neglected tropical diseases (NTDs), the Coalition for Epidemic Preparedness Innovations (CEPI) in preparation for future pandemics, and the International Monetary Fund (IMF) to enhance the global health system. Moreover, the role of Japanese Business Leaders’s Coalition for Global Health in collaboration with the Bill & Melida Gates Foundation in the field of innovative technology, such as an application of artificial intelligence (AI) for global health will be scrutinized. In addition, this research investigates implications of Japan’s Global Health Strategy for Japan’s global health diplomacy at the event of the G7/G8 summits, especially the 2023 G7 Hiroshima Summit. Finally, this book identifies multiple global health actors that constitute the emerging and changing global health architecture in the post-COVID-19 world.