Yunan County, located in the west of Guangdong Province, is under the jurisdiction of Yunfu City, Guangdong Province. The county borders Yun'an District in the east, Luoding City in the south, Cangwu County and Cenxi City in Wuzhou, Guangxi in the west, and Zhaoqing Fengkai County and Deqing County across the river in the north. As of 2019, the county has jurisdiction over 15 towns. The jurisdiction area is 1966.2 square kilometers. According to the data of the seventh population census, as of 0:00 on November 1, 2020, the permanent population of Yunan County was 371661.

The county seat is built along the Xijiang River. The Nanning-Guangzhou high-speed railway runs through the whole territory of Yunan. There are Yunan Station and Nanjiangkou Station in the county. G80 Guangzhou-Kunming Expressway and S26 Shenzhen-Luoyang Expressway pass through the territory. There are major scenic spots in the territory, such as Dawangshan National Forest Park, Dawan Nanjiang Ancient Dwelling Cultural Tourism Zone, Lanzhai Nanjiang Cultural Creative Base, and the site of Modao Mountain.

Yunan County belongs to Guilin County in the Qin Dynasty, Cangwu County in the Han Dynasty, and Duanxi County in the early Jin Dynasty. In the first year of Taikang in the Jin Dynasty (280 years), Duluo County was set up from Duanxi County; During the Yuanjia period of the Northern and Southern Dynasties, the two counties of Duluo and Wucheng were abolished and the Ducheng County was established; Xining County was officially established in 1577, the fifth year of Wanli in the Ming Dynasty; In the third year of the Republic of China (1914), it was renamed Yunan County; In 1958, it merged with Luoding County into Luonan County; In January 1959, it was renamed Luoding County; In April 1961, the system of Yunan County was restored; It was under the jurisdiction of Yunfu City in 1994.

In 2021, the county's GDP will reach 13.82 billion yuan, up 8.1% year on year and 5.5% on average in two years.