South Troy is an unincorporated community in Zumbro Township, Wabasha County, Minnesota, United States.The community is located south of Zumbro Falls, near the junction of U.S. Highway 63 and 568th Street.Nearby places include Hammond, Zumbro Falls, Mazeppa, Potsdam, and Oronoco. Wabasha County Roads 7 and 11 are nearby.South Troy had a post office from 1858 to 1903. Nearby Zumbro Falls was originally named Troy in the 1850s.