Brandeis University () is a private research university in Waltham, Massachusetts, United States. It is located within the Greater Boston area. Founded in 1948 as a non-sectarian, coeducational university, Brandeis was established on the site of the former Middlesex University. The university is named after Louis Brandeis, a former Justice of the U.S. Supreme Court.

Brandeis is classified among "R1: Doctoral Universities – Very high research activity" and is accredited by the New England Commission of Higher Education. The university has been a member of the Association of American Universities (AAU) since 1985. In 2018, it had a total enrollment of 5,820 students on a campus of 235 acres (95 hectares). The university has a liberal arts focus.

Alumni and faculty of the university have included Nobel Prize laureates Drew Weissman, Michael Rosbash, Jeffrey C. Hall, and Roderick MacKinnon, Fields Medalist Edward Witten, Turing Award Winner Leslie Lamport, and co-creators of the television show Friends David Crane and Marta Kauffman.