Fanshi County, is a county in Xinzhou City, in the northeast of Shanxi Province, China, bordering Hebei province to the southeast.

It is the easternmost county-level division of Xinzhou.

Fanshi County was one of the divisions of Yanmen Commandery under the Qin and Han.

Fanshi is located north of Mount Wutai and east of Daixian.

The primary industry of Fanshi county is gold mining.