Saint Mary-of-the-Woods, often called St. Mary's, is an unincorporated community in Sugar Creek Township in northwestern Vigo County, in the U.S. state of Indiana. The community is part of the Terre Haute Metropolitan Statistical Area. A large portion of Saint Mary-of-the-Woods along U.S. Route 150 is taken up by the grounds of the Sisters of Providence of Saint Mary-of-the-Woods, which contain the motherhouse of the Sisters of Providence as well as Saint Mary-of-the-Woods College. Although Saint Mary-of-the-Woods is unincorporated, it has a post office, with the ZIP code of 47876. It had a population of 797 at the 2010 census.