Hengyang is the second largest city of Hunan Province, China. It straddles the Xiang River about 160 km (99 mi) south of the provincial capital of Changsha. As of the 2020 Chinese census, Its total population was 6,645,243 inhabitants, whom 1,290,715 lived in the built-up area consisting of 4 urban districts, Nanyue District not being conurbated yet.

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.