From 24 July to 9 September 2024, France hosted the 33rd Summer Olympic Games and the 17th Paralympic Games, attracting visitors from all over the world. With sporting and celebratory events running simultaneously in the middle of the summer, hosting the Olympic and Paralympic Games was a major health safety challenge. This report reviews the work carried out by Santé publique France, the French national public health agency, in conjunction with the Ministry of Health and the various national and international public health stakeholders, to monitor and prevent health risks. This work leaves a useful legacy, such as new surveillance systems and new partnerships that have been developed. We wish to share this experience with all parties interested in protecting public health in the context of mass gatherings.