The Pearl River (Chinese: 珠江; pinyin: Zhūjiāng; lit. 'pearl river', or 粤江; 粵江; Yuèjiāng; 'Yue river') is an extensive river system in southern China. "Pearl River" is often also used as a catch-all for the watersheds of the Pearl tributaries within Guangdong, specifically the Xi ('west'), Bei ('north'), and Dong ('east'). These rivers all ultimately flow into the South China Sea through the Pearl River Delta. Measured from the farthest reaches of the Xi River, the Pearl–Xi–Xun–Qian–Hongshui–Nanpan 2,400 km (1,500 mi) Pearl River system constitutes China's third-longest, after the Yangtze River and the Yellow River, and its second largest by volume, after the Yangtze. The 453,700 km (175,200 sq mi) Pearl River Basin drains the majority of Guangdong and Guangxi provinces (collectively known as Liangguang), as well as parts of Yunnan, Guizhou, Hunan and Jiangxi; it also drains the northernmost parts of Vietnam's Northeast Cao Bằng and Lạng Sơn provinces. The Pearl River is famed as the river that flows through Guangzhou.
As well as referring to the system as a whole, the Pearl River name is applied to a specific branch within it. This Pearl River is the widest distributary within the delta, although notably short; the waters that converge east of the Bei are first referred to as the Pearl River just north of Guangzhou. The Pearl River's estuary, Bocca Tigris, is regularly dredged so as to keep it open for ocean vessels. The mouth of the Pearl River forms a large bay in the southeast of the delta, the Pearl River Estuary, the Bocca Tigris separates Shiziyang in the north, Lingdingyang in the south, and Jiuzhouyang at the southern tip of the estuary surrounded by the Wanshan Archipelago. This bay separates Macau and Zhuhai from Hong Kong and Shenzhen.