The Texas Hill Country is a vernacular term applied to a region of Central Texas, that features tall rugged hills that consist of thin layers of soil lying ontop of either limestone or granite. It also includes the Llano Uplift and the second largest granite monadnock in the United States, Enchanted Rock, which is located 18 miles (29 km) north of Fredericksburg. The Hill Country reaches into portions of the two major metropolitan areas of Central Texas, especially in San Antonio's northern suburbs and the western half of Travis County, ending just west of downtown Austin. The region is the eastern portion of the Edwards Plateau and the easternmost region of the American Southwest, and is bound by the Balcones Fault on the east and the Llano Uplift to the west and north. The terrain is punctuated by a large number of limestone or granite rocks and boulders and a thin layer of topsoil, which makes the region very dry and prone to flash flooding. The Texas Hill Country is also home to several native Southwestern types of vegetation, such as various yucca, Prickly Pear Cactus, and the dry Southwestern tree known as the Texas Live Oak.

Several cities were settled at the base of the Balcones Escarpment, including Austin, San Marcos, and New Braunfels, as a result of springs discharging water stored in the Edwards Aquifer.