Harper is a census-designated place (CDP) in Gillespie County, Texas, United States. The population was 1,006 at the 2000 census.
Harper is located at 30°18′04″N 99°14′36″W / 30.301009°N 99.243326°W / 30.301009; -99.243326 (30.301009, -99.243326). This is about 76 miles (122 km) northwest of San Antonio and 90 miles (145 km) west of Austin.
According to the United States Census Bureau, the CDP has a total area of 56.6 square miles (146.5 km2), all of it land.