The South Anna River is a principal tributary of the Pamunkey River, about 102 miles (164 km) long,[1] in central Virginia in the United States.

Via the Pamunkey and York rivers, it is part of the watershed of Chesapeake Bay.

According to the Geographic Names Information System, it has also been known as the Anna River.

[2] The South Anna River rises near Gordonsville in southwestern Orange County and flows generally southeastwardly and eastwardly through Louisa and Hanover counties.

The Ashland Mill Dam in Hanover County was built in 1916.