Sanxi () is a town in Yangxin County, Hubei, China. As of the 2017 census it had a population of 38,387 and an area of . It is surrounded by Yinzu Town of Daye City on the north, Wangying Town on the west, Futu Town on the east, and Military Reclamation State Farm on the south.
Sanxi means three streams. It is named Sanxi because Wangying Stream (), Daye Stream (), and Guohe Stream () meet in the town.
It was incorporated as a town in the Jiajing period (1522–1566) of the Ming dynasty (1368–1644). It was called Sanxikou Town () in the Ming dynasty. In the Qing dynasty (1644–1911), it was renamed "Sanxikou City" (). In 1935, it was the district seat of the Third District (). In 1952, it came under the jurisdiction of the Seventh District (). It was renamed "Sanxi Commune" () in 1958 and was renamed "Sanxi District" () in 1961.
The town is divided into one community and fifteen villages:
The highest point in the town is Mount Dawo () which stands above sea level. The lowest point is Li Lake (), which, at above sea level.
Wangying Stream (), Daye Stream (), and Guohe Stream () flow through the town.
The town is in the subtropical monsoon climate zone.
The town's agriculture is mainly rice, corn and vegetables.
The town is rich in manganese, coal, limestone, calcite, crystal stone, and marble.
G45 DaqingâÂÂGuangzhou Expressway passes across the town north to south.
Provincial Highway S317 travels through the town.
Sanjiaoshan () is a Buddhist temple in the town.