The COVID-19 pandemic (2019–2022) has drawn considerable attention to many aspects of health care which have been often ignored in the past. One of them is the link between human health and the health of other beings. The One Health concept recognizes the interconnectedness of human, animal, and environmental health, offering a holistic approach to address complex global health challenges. This chapter argues for the adoption of One Health, highlighting its significance in addressing zoonotic diseases, antimicrobial resistance, and climate change impacts on health. International initiatives and collaborations have endorsed One Health, aligning it with the United Nations’ Sustainable Development Goals (SDGs). Despite its importance, One Health implementation faces challenges, including inter-sectoral coordination, regulatory policies, funding, and political commitment. The G20 has a critical role in promoting One Health, and this chapter outlines a way forward for G20 leadership to advance this agenda. By embracing One Health, we can foster a more sustainable future, protecting the health of all.