What is the longest river entirely within a single country?

The Yangtze River is the longest river entirely within a single country. It flows wholly through China, from the Tibetan Plateau to its estuary on the East China Sea.

The river is about 6,236 kilometres long when its longest headwater route is included. It rises in the Tanggula Mountains and runs generally eastward through or alongside many major Chinese provinces and cities. Its drainage basin covers roughly one-fifth of China’s land area and supports nearly one-third of the country’s population.

The Yangtze has been central to Chinese agriculture, transport, commerce and settlement for thousands of years. The Three Gorges Dam, built on the river, is the world’s largest hydroelectric power station by installed capacity. The fertile Yangtze Delta is also one of China’s major economic regions.

The common mistake is choosing the Amazon or Nile because they are longer in global rankings. Those rivers cross multiple countries; the Yangtze is the longest major river whose course remains within one national boundary.