Lost Creek is an affluent upper-middle-class neighborhood and census-designated place (CDP) in Travis County, Texas, United States. The population was 1,276 at the 2020 census. The census tract is bordered by Capital of Texas Highway to the east, Barton Creek to the south, Barton Creek Boulevard to the west, and Bee Caves Road to the north. The Lost Creek CDP encompasses several small neighborhoods—Parkstone, Woods of Westlake, Camelot, and Knollwood—as well as the largest and most populous Lost Creek neighborhood.