The largest body of water in the world is the Pacific Ocean. Covering more than 63 million square miles (165 million square kilometers), it extends from the Arctic Ocean in the north to the Southern Ocean in the south, and borders several countries across Asia, Australia, North America, and South America. The Pacific Ocean is not only the largest ocean but also the deepest, featuring the Mariana Trench, which reaches depths of about 36,000 feet (approximately 11,000 meters). It plays a crucial role in global climate regulation and biodiversity, hosting a diverse range of marine life and ecosystems.