Hunan is an inland province of China. Located in the middle reaches of the Yangtze watershed, it borders the province-level divisions of Hubei to the north, Jiangxi to the east, Guangdong and Guangxi to the south, Guizhou to the west, and Chongqing to the northwest. Its capital and largest city is Changsha, which abuts the Xiang River. Hengyang, Zhuzhou, and Yueyang are among its most populous urban cities. With a population of just over 66 million as of 2020 residing in an area of approximately 210,000 km2 (81,000 sq mi), it is China's 7th most populous province, the fourth most populous among landlocked provinces, the second most populous in South Central China after Guangdong and the most populous province in Central China. It is the largest province in South-Central China, the fourth largest among landlocked provinces, and the 10th most extensive province by area.

Yangtze or Yangzi is the longest river in Eurasia, the third-longest in the world. It rises at Jari Hill in the Tanggula Mountains of the Tibetan Plateau and flows 6,300 km (3,915 mi) in a generally easterly direction to the East China Sea. It is the fifth-largest primary river by discharge volume in the world. Its drainage basin comprises one-fifth of the land area of China, and is home to nearly one-third of the country's population.