Round Rock is a city in Williamson and Travis County, Texas, United States, part of the Greater Austin metropolitan area. Its population is 119,468 according to the 2020 census. The city straddles the Balcones Escarpment, a fault line in which the areas roughly east of Interstate 35 are flat and characterized by having black, fertile soils of the Blackland Prairie, and the west side of the Escarpment, which consists mostly of hilly, karst-like terrain with little topsoil and higher elevations and which is part of the Texas Hill Country. Located about 20 miles (32 km) north of downtown Austin, Round Rock shares a common border with Austin near Texas State Highway 45. Round Rock is the international headquarters of Dell, which employs about 16,000 people at its Round Rock facilities. Retailers in Round Rock include IKEA, Premium Outlets, and the mixed-use La Frontera center.