South China Sea is the dominant term used in English for the sea, and the name in most European languages is equivalent. This name is a result of early European interest in the sea as a route from Europe and South Asia to the trading opportunities of China. In the sixteenth century Portuguese sailors called it the China Sea (Mare da China); later needs to differentiate it from nearby bodies of water led to calling it the South China Sea. The International Hydrographic Organization refers to the sea as "South China Sea (Nan Hai)".
The Yizhoushu, which was a chronicle of the Western Zhou dynasty (1046–771 BCE) gives the first Chinese name for the South China Sea as Nanfang Hai (Chinese: 南方海; pinyin: Nánfāng Hǎi; literally: 'Southern Sea'), claiming that barbarians from that sea gave tributes of hawksbill sea turtles to the Zhou rulers. The Classic of Poetry, Zuo Zhuan, and Guoyu classics of the Spring and Autumn period (771–476 BCE) also referred to the sea, but by the name Nan Hai (Chinese: 南海; pinyin: Nán Hǎi; literally: 'South Sea') in reference to the State of Chu's expeditions there. Nan Hai, the South Sea, was one of the Four Seas of Chinese literature. There are three other seas, one for each of the four cardinal directions. During the Eastern Han dynasty (23–220 CE), China's rulers called the Sea Zhang Hai (Chinese: 漲海; pinyin: Zhǎng Hǎi; literally: 'distended sea'). Fei Hai (Chinese: 沸海; pinyin: Fèi Hǎi; literally: 'boil sea') became popular during the Southern and Northern Dynasties period. Usage of the current Chinese name, Nan Hai (South Sea), became gradually widespread during the Qing Dynasty.
In Southeast Asia it was once called the Champa Sea or Sea of Cham, after the maritime kingdom of Champa that flourished there before the sixteenth century. The majority of the sea came under Japanese naval control during World War II following the military acquisition of many surrounding South East Asian territories in 1941. Japan calls the sea Minami Shina Kai "South China Sea". This was written 南支那海 until 2004, when the Japanese Foreign Ministry and other departments switched the spelling to 南シナ海, which has become the standard usage in Japan.
In China, it is called the "South Sea", 南海 Nánhǎi, and in Vietnam the "East Sea", Biển Đông. In Malaysia, Indonesia and the Philippines, it was long called the "South China Sea" (Dagat Timog Tsina in Tagalog, Laut China Selatan in Malay), with the part within Philippine territorial waters often called the "Luzon Sea", Dagat Luzon, by the Philippines. However, following an escalation of the Spratly Islands dispute in 2011, various Philippine government agencies started using the name "West Philippine Sea". A Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) spokesperson said that the sea to the east of the Philippines will continue to be called the Philippine Sea.
In September 2012, Philippine President Benigno Aquino III signed Administrative Order No. 29, mandating that all government agencies use the name "West Philippine Sea" to refer to the parts of the South China Sea within the Philippines' exclusive economic zone, including the Luzon Sea as well as the waters around, within and adjacent to the Kalayaan Island Group and Bajo de Masinloc, and tasked the National Mapping and Resource Information Authority (NAMRIA) to use the name in official maps.
In July 2017, to assert its sovereignty, Indonesia renamed the northern reaches of its exclusive economic zone in the South China Sea as the "North Natuna Sea", which is located north of the Indonesian Natuna Islands, bordering the southern Vietnam exclusive economic zone, corresponding to the southern end of the South China Sea. The "Natuna Sea" is located south of Natuna Island within Indonesian territorial waters. Therefore, Indonesia has named two seas that are portions of the South China Sea; the Natuna Sea located between Natuna Islands and the Lingga and Tambelan Archipelagos, and the North Natuna Sea located between the Natuna Islands and Cape Cà Mau on the southern tip of the Mekong Delta in Vietnam.