| Hunyuan County | |
| Other Name: | Hun-yüan |
| Postal Code Type: | Postal code |
| Postal Code: | 037400 |
| Settlement Type: | County |
| Pushpin Map: | China Shanxi |
| Pushpin Label: | Hunyuan |
| Pushpin Map Caption: | Location in Shanxi |
| Subdivision Type: | Country |
| Subdivision Name: | People's Republic of China |
| Subdivision Type1: | Province |
| Subdivision Name1: | Shanxi |
| Subdivision Type2: | Prefecture-level city |
| Subdivision Name2: | Datong |
| Area Total Km2: | 1965 |
| Population: | 237749 |
| Population As Of: | 2020 |
| Population Density Km2: | auto |
| Coordinates: | 39.69°N 113.68°W |
| Timezone: | China Standard |
| Utc Offset: | +8 |
| Order: | st |
| T: | 渾源縣 |
| S: | 浑源县 |
| P: | Húnyuán Xiàn |
| J: | wan4jyun4 jyun2 |
| Pic: | 浑源永安寺.jpg |
| Piccap: | Yong'an Temple, Hunyuan |
| Also Known As: | Guo County |
| P2: | Guōxiàn Guō Xiàn |
| W2: | Kuo-hsien Kuo Hsien |
| J2: | gwok3 jyun2 |
Hunyuan County is a county under the administration of Datong City, in the northeast of Shanxi province, China.
During the Spring and Autumn period of Chinese history, present-day Hunyuan County formed part of the Baidi state of Dai to the north of the Zhou Kingdom. It was conquered by the Zhao clan of Jin.
Under the Han, was established and placed under Yanmen Commandery and was established and placed under Dai Commandery. Pingshu was later merged with Guo County, which was placed in Hengshan Commandery. During the Jianwu era of the Eastern Han, Guo County was renamed. During the Three Kingdoms, Wei restored the name Guo. This was changed to Guoshan County by the Northern Wei, who placed it under the administration of Si Prefecture. Under the Tang, it was placed in Yun Prefecture.
The 1,500-year-old Hanging Temple is an important and unique structure within the Datong area.
In 2010 the population of the district was 343,486 inhabitants.