The South East Asia Sea is a marginal sea
- south of China and Taiwan,
- west of the Philippines,
- north west of Sabah (Malaysia), Sarawak (Malaysia) and Brunei,
- north of Indonesia,
- north east of the Malay peninsula (Malaysia) and Singapore, and
- east of Vietnam.
It is a part of the Pacific Ocean, encompassing an area from Singapore to the Strait of Taiwan of around 3,500,000 km². It is one of the largest sea bodies after the five oceans. The minute South China Sea Islands, collectively an archipelago, number in the hundreds. The sea and its mostly uninhabited islands are subject to competing claims of sovereignty by several countries. These claims are also reflected in the variety of names used for the islands and the sea.