Windthorst is a town in Archer and Clay counties in Texas, United States. It is part of the Wichita Falls, Texas Metropolitan Statistical Area. The population was 342 at the 2020 census. The town is named for Ludwig Windthorst, a Catholic statesman in Germany. Windthorst is the home of the St. Mary's Grotto, a Roman Catholic outdoor shrine, which was paid for with money sent home by 64 military service members from Windthorst who served in World War II. All of the 64 returned home.