The Austin–Round Rock–San Marcos metropolitan statistical area, or Greater Austin, is a five-county metropolitan area in the U.S. state of Texas, as defined by the Office of Management and Budget. The metropolitan area is situated in Central Texas on the western edge of the American South and on the eastern edge of the American Southwest, and borders Greater San Antonio to the south. It forms part of the larger San Antonio-Austin Metroplex.

As of the 2020 U.S. census, the Austin–Round Rock–San Marcos MSA is the 26th-largest metropolitan area in the United States, with a total population of 2,352,426. The metropolitan area contains the city of Austin—the fourth-largest city in Texas and the 10th-largest city in the United States with a population of 974,447 people. Austin's largest suburbs are Round Rock, Cedar Park, Georgetown, San Marcos, Leander, and Pflugerville.

Archeologists divide the Texas prehistoric archeological record into five general periods: pre-Clovis (ca. 18,000 plus –13,400 year ago), Paleoindian (13,400–10,000 years ago), Archaic (10,000 years ago to ca. 2000 years ago), Woodland (ca. 2500–1150 years ago; select regions), and the Late Prehistoric (ca. 1250–1150–420 years ago). All but the Woodland period are applicable to the Greater Austin area. Some research adds what is called the Protohistoric period, the short period of first contact between Indigenous Peoples and Europeans (Spanish and French) upon their first arrival; it is before the start of what is considered historic times.

The earliest known inhabitants of the area, during the late Pleistocene (Ice Age), date to between 12,000 to 22,000 years ago as evidenced by the Gault (archaeological site) just west of Williamson County and the Wilson-Leonard Site, best known for the discovery of Leanderthal Lady ("Leanne") at the Wilson-Leonard site near Leander, Texas. But archeology dig sites show a much greater evidence of Archaic Period inhabitants has been recovered from burned rock middens and rock shelters near Round Rock along Brushy Creek, in Georgetown along the San Gabriel River, and in Austin especially near Barton Springs. The prehistory of Texas has been studied by both professional and avocational archeologists for many decades. Pre-historic campsites are found throughout the county along streams or other water sources; most are "open occupation" sites, though caves and rockshelters are often found along various rivers and streams.

Native American Coahuiltecan descendants include Barton Springs among the four springs part of their creation story dating to prehistoric times; these springs are Comal Springs, Barton Springs, San Marcos Springs and San Antonio Springs. While there were many other tribes associated with the Greater Austin area, the present territory of central Texas was not the long-term ancestral homeland of any indigenous group for whom an ethnographic account exists. The ethnographically well-known Comanche, Lipan Apache, Waco and even the Tonkawa arrived in central Texas just before or during the early European contact period."

Spanish explorers, including the Espinosa-Olivares-Aguirre expedition, traveled through the area for centuries though few permanent settlements were created for some time. In the mid-18th century the San Xavier missions were established along the San Gabriel River in what is now western Milam County to facilitate exploration.

In 1804 the fort Puesta del Colorado was established by the Spanish in what is now Bastrop. In 1807 the San Marcos de Neve settlement (modern San Marcos) was established on the San Marcos River. Following the independence of Mexico, of which Texas was a part, the empresario Stephen F. Austin issued grants to settlers in what is now Bastrop and Fayette Counties. During the mid-1820s settlements were established along the Colorado River near modern La Grange. The village of Mina (later renamed Bastrop) was established in 1827. Growth of the settlements was stagnant for some time because of conflicts with the Native Americans in the region. Nevertheless, the region sat along an important trade route known as the Camino Real de los Tejas, which ran from Mexico, though San Antonio and San Marcos, to Natchitoches. During the 1830s others, such as Martín Veramendi and Thomas G. McGehee, were issued land grants by the Mexican government to encourage settlement in the region. A string of forts was established east of modern Austin in what was then the western frontier.

In 1835 Texans fought for independence in the Texas Revolution and won. Following independence other settlements were gradually established including Waterloo and Brushy Creek (modern Round Rock). In 1839 a commission appointed by Texas President Mirabeau B. Lamar selected Waterloo as the site for the new capital and the name Austin was chosen as the town's new name. In 1840 a series of conflicts between the Texas Rangers and the Comanches known as the Council House Fight and the Battle of Plum Creek finally pushed the Comanches westward mostly ending conflicts in Central Texas. Settlement in the area began to expand quickly. Travis County was established in 1840 and the surrounding counties were mostly established within the next two decades. New settlements were established such as Hamilton (now Burnet) in 1852.