The Khaled bin Sultan Living Oceans Foundation embarked on the Global Reef Expedition—the largest coral reef survey and mapping expedition in history—to study the health and resilience of coral reefs around the world. On the Expedition, the Foundation quantitively measured and categorized coral reef environments in three regions in Tonga: Ha’apai, Vava’u, and around the island of Niuatoputapu. The research mission assessed the impact of anthropogenic and natural disturbances on reef ecosystems, such as pollution, climate change, overfishing, storm damage, and Crown-of-Thorns Starfish (COTS) outbreaks. The Global Reef Expedition: Kingdom of Tonga Final Report presents the Foundation’s findings from this Expedition and provides scientists, managers, and stakeholders recommendations that are indispensable for the management and protection of Tonga’s coral reefs.