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 in Virginia by student enrollment. 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". Two of the university's professors have received the Nobel Memorial Prize in Economics: James M. Buchanan in 1986 and Vernon L. Smith in 2002.