The biggest ocean on Earth is the Pacific Ocean. Spanning an area of approximately 63 million square miles, the Pacific Ocean is larger than all the Earth's landmasses combined. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bordered by Asia and Australia on the west and the Americas on the east. The Pacific is known for its vastness and depth, containing the Mariana Trench, which is the deepest part of the ocean. It plays a crucial role in global weather patterns and marine biodiversity.