George Mason University (GMU) is a public research university in Fairfax County, Virginia, United States. Located in Northern Virginia near Washington, D.C., the university is named in honor of George Mason, a Founding Father of the United States.

The university was founded in 1949 as a northern branch of the University of Virginia. It became an independent university in 1972, and it has since grown into the largest public university by student enrollment in Virginia. It has expanded into a residential college for traditional students while maintaining its historic commuter student-inclusive environment at both undergraduate and post-graduate levels, with an emphasis on combining modern professional education with a traditional liberal arts curriculum.

The university operates four campuses; the flagship campus is in the Fairfax, Virginia area. Its other three campuses are in Arlington, Front Royal, and Prince William County. It also operates a retreat and conference center in Lorton and an international campus in Incheon, South Korea. It is classified among "R1: Doctoral Universities – Very high research activity". Since the university's founding, two of its economics professors have received the Nobel Memorial Prize in Economics: James M. Buchanan in 1986 and Vernon L. Smith in 2002.

In 1949, the University of Virginia created an extension center to serve mid-career working professionals and non-traditional students near urban centers in the Northern Virginia suburbs of Washington, D.C. The extension center offered both for credit and non-credit informal classes in the evenings at various pre-existing venues. The first for credit classes offered were: "Government in the Far East, Introduction to International Politics, English Composition, Principles of Economics, Mathematical Analysis, Introduction to Mathematical Statistics, and Principles of Lip Reading." By the end of 1952, enrollment was 1,192 students.

A resolution of the Virginia General Assembly in January 1956 changed the extension center into University College, the Northern Virginia branch of the University of Virginia.^{[self-published source?]} John Norville Gibson Finley served as director. Seventeen freshmen students attended classes at University College in a small renovated elementary school building in Bailey's Crossroads starting in September 1957. In 1958 University College became George Mason College.

The City of Fairfax purchased and donated 150 acres (60 hectares) of land just south of the city limits to the University of Virginia for the college's new site, which is now referred to as the Fairfax Campus. In 1959, the Board of Visitors of the University of Virginia selected a permanent name for the college: George Mason College of the University of Virginia. The Fairfax campus construction planning that began in early 1960 showed visible results when the development of the first 40 acres (16 hectares) of Fairfax Campus began in 1962. In the Fall of 1964 the new campus welcomed 356 students.^{[self-published source?]}

In 1966, in the Virginia General Assembly, Alexandria delegate James M. Thomson, with the backing of the University of Virginia, introduced a bill in the General Assembly to make George Mason College a four-year institution under the University of Virginia's direction. The measure, known as H 33, passed the Assembly easily and was approved on March 1, 1966, making George Mason College a degree-granting institution. During that same year, the local jurisdictions of Fairfax County, Arlington County, and the cities of Alexandria and Falls Church agreed to appropriate $3 million to purchase land adjacent to Mason to provide for a 600-acre (240-hectare) Fairfax Campus with the intention that the institution would expand into a regional university of major proportions, including the granting of graduate degrees.^{[citation needed]}

In 1972, Virginia separated George Mason College from the University of Virginia in Charlottesville and renamed it George Mason University.