Dongkou County is a county located in west-central Hunan Province, China. It operates under the administration of Shaoyang City and covers a total area of 2,200 km² (850 sq mi).
The county is bordered by Longhui County to the northeast, Xupu County and Hongjiang City to the northwest, Suining County to the southwest, and Xinning County to the southeast. As of 2015, Dongkou had a registered population of 870,900 and a permanent resident population of 784,500.
The administrative divisions of the county include 11 towns, nine townships, and three subdistricts. The county seat is located in Wenchang Subdistrict.