Another three have been reported missing in the region due to the flooding and more than 2,700 houses have been damaged, said provincial official Li Dajian.
More than a week of torrential rain and storms have battered the province, reported Chinese state media.
According to some monitoring stations in Hunan, this is a historic level of rainfall the province has witnessed, reported Xinhua, without specifying the amount of recorded rain.
Heavy rain has affected around 1.8 million in the rural province and damaged more than 2,700 houses out of which some have collapsed completely, reported Xinhua.
A landslide also buried parts of a town in the Guangxi region.
Rescue workers were still looking for survivors in Xinfeng township on Thursday as hillsides reeled under waterlogging from days of rain, making the terrain slippery, state broadcaster CCTV reported.
One woman died in the landslide and another was rescued in the area, the report added.
Officials have issued warnings of heavy rain in Guangxi and the nearby provinces of Jiangxi, Fujian, Guangdong, Hainan, Sichuan, Chongqing and Yunnan, reported Xinhua.
Drivers and school authorities have been asked to take safety precautions.
Heavy flooding due to strong downpour in China has been regular in summer months recently, especially in central and southern areas which receive the most rainfall.
China saw its worst floods in a decade last year after rain and flooding in central regions killed more than 300 people.
Experts have pointed out that changing weather phenomenon and increased tropical storms are being caused by the climate crisis, directly threatening humans, crops and groundwater quality.
Additional reporting from agencies